feat(ui): add custom theme color support and share app functionality

Introduce a new custom theme feature that allows users to personalize the application background color using RGB sliders, hex input, or a set of predefined palettes.

Key changes include:
* **Custom Theme Engine**: Added `CustomThemeFragment` and `ThemeHelper` to manage color selection and application. The UI dynamically updates the background color across the `MainActivity` and `PlayerFragment` when preferences change.
* **Android TV Support**: Provided a specialized layout for television devices (`fragment_custom_theme.xml` in `layout-television`) with optimized focus handling for D-pad navigation.
* **Share Feature**: Implemented a "Share App" preference in `SettingsFragment` that triggers a standard Android share intent and displays a thank-you notification upon use.
* **Localization**: Added Ukrainian language support and updated string resources for multiple locales (DE, DA, EL, FR, JA, NL, PL, RU) to include the new theme and share options.
* **Persistence**: Updated `PreferencesHelper` and `Keys` to store theme-related settings, including the enabled state, selected color, and predefined color index.

app/src/main/java/com/michatec/radio/CustomThemeFragment.kt

@@ -0,0 +1,207 @@
+package com.michatec.radio
+
+import android.content.ClipData
+import android.content.ClipboardManager
+import android.content.Context
+import android.content.pm.PackageManager
+import android.graphics.Color
+import android.graphics.drawable.GradientDrawable
+import android.os.Bundle
+import android.text.Editable
+import android.text.TextWatcher
+import android.view.LayoutInflater
+import android.view.View
+import android.view.ViewGroup
+import android.widget.SeekBar
+import android.widget.Toast
+import androidx.appcompat.app.AppCompatActivity
+import androidx.core.graphics.toColorInt
+import androidx.fragment.app.Fragment
+import androidx.recyclerview.widget.GridLayoutManager
+import androidx.recyclerview.widget.RecyclerView
+import com.google.android.material.textfield.TextInputEditText
+import com.michatec.radio.helpers.PreferencesHelper
+import com.michatec.radio.helpers.ThemeHelper
+
+class CustomThemeFragment : Fragment() {
+
+    private lateinit var colorPreview: View
+    private lateinit var hexCode: TextInputEditText
+    private lateinit var seekRed: SeekBar
+    private lateinit var seekGreen: SeekBar
+    private lateinit var seekBlue: SeekBar
+    private lateinit var recyclerView: RecyclerView
+
+    private var currentColor: Int = Color.BLACK
+    private var isUpdatingFromHex = false
+
+    private fun applyColor(
+        color: Int
+    ) {
+        updateSeekBars(color)
+        updatePreview(color)
+    }
+
+    private val isAndroidTV: Boolean by lazy {
+        requireContext().packageManager.hasSystemFeature(PackageManager.FEATURE_LEANBACK)
+    }
+
+    override fun onCreateView(
+        inflater: LayoutInflater, container: ViewGroup?,
+        savedInstanceState: Bundle?
+    ): View? {
+        return inflater.inflate(R.layout.fragment_custom_theme, container, false)
+    }
+
+    override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
+        super.onViewCreated(view, savedInstanceState)
+
+        (activity as? AppCompatActivity)?.supportActionBar?.title = getString(R.string.pref_custom_theme_title)
+
+        colorPreview = view.findViewById(R.id.color_preview)
+        hexCode = view.findViewById(R.id.hex_code)
+        seekRed = view.findViewById(R.id.seek_red)
+        seekGreen = view.findViewById(R.id.seek_green)
+        seekBlue = view.findViewById(R.id.seek_blue)
+        recyclerView = view.findViewById(R.id.color_recycler_view)
+
+        currentColor = PreferencesHelper.loadCustomThemeColor(requireContext())
+
+        applyColor(currentColor)
+
+        val seekBarListener = object : SeekBar.OnSeekBarChangeListener {
+            override fun onProgressChanged(seekBar: SeekBar?, progress: Int, fromUser: Boolean) {
+                if (fromUser) {
+                    val r = seekRed.progress
+                    val g = seekGreen.progress
+                    val b = seekBlue.progress
+                    currentColor = Color.rgb(r, g, b)
+                    updatePreview(currentColor)
+                    PreferencesHelper.saveCustomTheme(currentColor, -1)
+                    (recyclerView.adapter as? ColorAdapter)?.resetSelection()
+                }
+            }
+            override fun onStartTrackingTouch(seekBar: SeekBar?) {}
+            override fun onStopTrackingTouch(seekBar: SeekBar?) {}
+        }
+
+        seekRed.setOnSeekBarChangeListener(seekBarListener)
+        seekGreen.setOnSeekBarChangeListener(seekBarListener)
+        seekBlue.setOnSeekBarChangeListener(seekBarListener)
+
+        // Clipboard logic (Non-TV)
+        if (!isAndroidTV) {
+            hexCode.setOnClickListener {
+                copyToClipboard(hexCode.text.toString())
+            }
+            hexCode.addTextChangedListener(object : TextWatcher {
+                override fun beforeTextChanged(s: CharSequence?, start: Int, count: Int, after: Int) {}
+                override fun onTextChanged(s: CharSequence?, start: Int, before: Int, count: Int) {
+                    if (!isUpdatingFromHex) {
+                        try {
+                            val color = s.toString().toColorInt()
+                            currentColor = color
+                            isUpdatingFromHex = true
+                            applyColor(color)
+                            PreferencesHelper.saveCustomTheme(currentColor, -1)
+                            (recyclerView.adapter as? ColorAdapter)?.resetSelection()
+                            isUpdatingFromHex = false
+                        } catch (_: Exception) {}
+                    }
+                }
+                override fun afterTextChanged(s: Editable?) {}
+            })
+        } else {
+            hexCode.isFocusable = false
+            hexCode.isFocusableInTouchMode = false
+        }
+
+        setupRecyclerView()
+    }
+
+    private fun copyToClipboard(text: String) {
+        val clipboard = requireContext().getSystemService(Context.CLIPBOARD_SERVICE) as ClipboardManager
+        val clip = ClipData.newPlainText(getString(R.string.hex_code), text)
+        clipboard.setPrimaryClip(clip)
+        Toast.makeText(requireContext(), R.string.toastmessage_copied_to_clipboard, Toast.LENGTH_SHORT).show()
+    }
+
+    private fun updateSeekBars(color: Int) {
+        seekRed.progress = Color.red(color)
+        seekGreen.progress = Color.green(color)
+        seekBlue.progress = Color.blue(color)
+    }
+
+    private fun updatePreview(color: Int) {
+        colorPreview.setBackgroundColor(color)
+        if (!isUpdatingFromHex) {
+            isUpdatingFromHex = true
+            hexCode.setText(String.format("#%08X", 0xFFFFFF and color))
+            isUpdatingFromHex = false
+        }
+    }
+
+    private fun setupRecyclerView() {
+        recyclerView.layoutManager = GridLayoutManager(requireContext(), 5)
+        val colors = ThemeHelper.getPredefinedColors(requireContext())
+        val adapter = ColorAdapter(colors) { color, index ->
+            currentColor = color
+            applyColor(color)
+            PreferencesHelper.saveCustomTheme(currentColor, index)
+        }
+        recyclerView.adapter = adapter
+    }
+
+    private inner class ColorAdapter(
+        private val colors: List<Int>,
+        private val onColorSelected: (Int, Int) -> Unit
+    ) : RecyclerView.Adapter<ColorAdapter.ViewHolder>() {
+
+        private var selectedPosition: Int = -1
+
+        init {
+            selectedPosition = PreferencesHelper.loadCustomThemeIndex()
+        }
+
+        fun resetSelection() {
+            val oldPos = selectedPosition
+            selectedPosition = -1
+            if (oldPos != -1) notifyItemChanged(oldPos)
+        }
+
+        inner class ViewHolder(view: View) : RecyclerView.ViewHolder(view) {
+            val circle: View = view.findViewById(R.id.color_circle)
+            init {
+                view.isFocusable = true
+                view.isFocusableInTouchMode = isAndroidTV
+                view.setOnClickListener {
+                    val pos = bindingAdapterPosition
+                    if (pos != RecyclerView.NO_POSITION) {
+                        val oldPos = selectedPosition
+                        selectedPosition = pos
+                        if (oldPos != -1) notifyItemChanged(oldPos)
+                        notifyItemChanged(selectedPosition)
+                        onColorSelected(colors[pos], pos)
+                    }
+                }
+            }
+        }
+
+        override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): ViewHolder {
+            val view = LayoutInflater.from(parent.context)
+                .inflate(R.layout.element_color_circle, parent, false)
+            return ViewHolder(view)
+        }
+
+        override fun onBindViewHolder(holder: ViewHolder, position: Int) {
+            val color = colors[position]
+            val drawable = holder.circle.background as GradientDrawable
+            drawable.setColor(color)
+            
+            // Set selection state
+            holder.itemView.isSelected = (position == selectedPosition)
+        }
+
+        override fun getItemCount() = colors.size
+    }
+}

app/src/main/java/com/michatec/radio/Keys.kt

@@ -92,6 +92,9 @@ object Keys {
     const val PREF_PRESET_DRC: String = "PRESET_DRC"
     const val PREF_PRESET_STEREO_WIDTH: String = "PRESET_STEREO_WIDTH"
     const val PREF_LANGUAGE_SELECTED: String = "PRESET_LANGUAGE_SELECTED"
+    const val PREF_CUSTOM_THEME_COLOR: String = "CUSTOM_THEME_COLOR"
+    const val PREF_CUSTOM_THEME_ENABLED: String = "CUSTOM_THEME_ENABLED"
+    const val PREF_CUSTOM_THEME_INDEX: String = "CUSTOM_THEME_INDEX"
 
     // default const values
     const val DEFAULT_SIZE_OF_METADATA_HISTORY: Int = 25

app/src/main/java/com/michatec/radio/MainActivity.kt

@@ -7,6 +7,7 @@ import android.content.SharedPreferences
 import android.content.pm.PackageManager
 import android.content.res.Configuration
 import android.net.Uri
+import android.util.TypedValue
 import android.os.Build
 import android.os.Bundle
 import android.os.Handler
@@ -28,6 +29,7 @@ import com.michatec.radio.helpers.AppThemeHelper
 import com.michatec.radio.helpers.FileHelper
 import com.michatec.radio.helpers.LanguageHelper
 import com.michatec.radio.helpers.PreferencesHelper
+import com.michatec.radio.helpers.ThemeHelper
 import org.woheller69.freeDroidWarn.FreeDroidWarn
 import java.util.Locale
 
@@ -38,6 +40,7 @@ class MainActivity : AppCompatActivity() {
 
     /* Main class variables */
     private lateinit var appBarConfiguration: AppBarConfiguration
+    private lateinit var mainRoot: View
 
     // Check if the device running the app is an Android TV instance
     private val isAndroidTV: Boolean by lazy {
@@ -94,6 +97,8 @@ class MainActivity : AppCompatActivity() {
 
         // set up views
         setContentView(R.layout.activity_main)
+        mainRoot = findViewById(R.id.main_root)
+        applyCustomTheme()
 
         // create .nomedia file - if not yet existing
         FileHelper.createNomediaFile(getExternalFilesDir(null))
@@ -136,6 +141,33 @@ class MainActivity : AppCompatActivity() {
         }
     }
 
+    private fun applyCustomTheme() {
+        val enabled = PreferencesHelper.loadCustomThemeEnabled()
+        if (enabled) {
+            var color = PreferencesHelper.loadCustomThemeColor(this)
+            val index = PreferencesHelper.loadCustomThemeIndex()
+            
+            if (index != -1) {
+                // Color belongs to a predefined group. Update it based on current mode.
+                val colors = ThemeHelper.getPredefinedColors(this)
+                if (index < colors.size) {
+                    val updatedColor = colors[index]
+                    if (updatedColor != color) {
+                        color = updatedColor
+                        // Save the updated color to keep preferences in sync with the current mode
+                        PreferencesHelper.saveCustomThemeColor(color)
+                    }
+                }
+            }
+            mainRoot.setBackgroundColor(color)
+        } else {
+            // Reset to default theme background color
+            val typedValue = TypedValue()
+            theme.resolveAttribute(android.R.attr.colorBackground, typedValue, true)
+            mainRoot.setBackgroundColor(typedValue.data)
+        }
+    }
+
 
     /* Overrides onResume from AppCompatActivity */
     override fun onResume() {
@@ -176,6 +208,9 @@ class MainActivity : AppCompatActivity() {
                 Keys.PREF_LANGUAGE_SELECTED -> {
                     LanguageHelper.setLanguage(this, PreferencesHelper.loadSelectedLanguage())
                 }
+                Keys.PREF_CUSTOM_THEME_COLOR, Keys.PREF_CUSTOM_THEME_ENABLED, Keys.PREF_CUSTOM_THEME_INDEX -> {
+                    applyCustomTheme()
+                }
             }
         }
     /*

app/src/main/java/com/michatec/radio/PlayerFragment.kt

@@ -308,6 +308,9 @@ class PlayerFragment : Fragment(),
         if (key == Keys.PREF_PLAYER_METADATA_HISTORY) {
             requestMetadataUpdate()
         }
+        if (key == Keys.PREF_CUSTOM_THEME_COLOR || key == Keys.PREF_CUSTOM_THEME_ENABLED || key == Keys.PREF_CUSTOM_THEME_INDEX) {
+            layout.applyCustomTheme(activity as Context)
+        }
     }
 
 

app/src/main/java/com/michatec/radio/SettingsFragment.kt

@@ -265,6 +265,7 @@ class SettingsFragment : PreferenceFragmentCompat(), YesNoDialog.YesNoDialogList
             return@setOnPreferenceClickListener true
         }
 
+        // set up "Visualizer" preference entry
         val preferenceVisualizer = Preference(context)
         preferenceVisualizer.title = getString(R.string.pref_visualizer_title)
         preferenceVisualizer.setIcon(R.drawable.ic_visualizer_24dp)
@@ -349,6 +350,7 @@ class SettingsFragment : PreferenceFragmentCompat(), YesNoDialog.YesNoDialogList
             return@setOnPreferenceClickListener true
         }
 
+        // set up "Language Selection" preference
         val preferenceLanguageSelection = Preference(context)
         preferenceLanguageSelection.title = getString(R.string.pref_language_selection_title)
         preferenceLanguageSelection.setIcon(R.drawable.ic_language_24dp)
@@ -361,6 +363,61 @@ class SettingsFragment : PreferenceFragmentCompat(), YesNoDialog.YesNoDialogList
             return@setOnPreferenceClickListener true
         }
 
+        // set up "Custom Theme" preference
+        val preferenceCustomTheme = Preference(context)
+        preferenceCustomTheme.title = getString(R.string.pref_custom_theme_title)
+        preferenceCustomTheme.setIcon(R.drawable.ic_rbrush_24dp)
+        preferenceCustomTheme.summary = getString(R.string.pref_custom_theme_summary)
+        preferenceCustomTheme.isEnabled = PreferencesHelper.loadCustomThemeEnabled()
+        preferenceCustomTheme.setOnPreferenceClickListener {
+            findNavController().navigate(R.id.action_settings_to_cstheme)
+            return@setOnPreferenceClickListener true
+        }
+
+        // set up "Custom Theme Enabled" preference
+        val preferenceCustomThemeEnabled = MarqueeSwitchPreference(context)
+        preferenceCustomThemeEnabled.title = getString(R.string.pref_custom_theme_enabled_title)
+        preferenceCustomThemeEnabled.setIcon(R.drawable.ic_rbrush_24dp)
+        preferenceCustomThemeEnabled.summaryOn = getString(R.string.pref_custom_theme_enabled_summary)
+        preferenceCustomThemeEnabled.summaryOff = getString(R.string.pref_custom_theme_disabled_summary)
+        preferenceCustomThemeEnabled.key = Keys.PREF_CUSTOM_THEME_ENABLED
+        preferenceCustomThemeEnabled.setDefaultValue(PreferencesHelper.loadCustomThemeEnabled())
+        preferenceCustomThemeEnabled.setOnPreferenceChangeListener { _, newValue ->
+            when (newValue) {
+                true -> {
+                    // enable custom theme
+                    preferenceCustomTheme.isEnabled = true
+                }
+                false -> {
+                    // disable custom theme
+                    preferenceCustomTheme.isEnabled = false
+                }
+            }
+            return@setOnPreferenceChangeListener true
+        }
+
+        // set up "Share the App" preference
+        val preferenceShareApp = Preference(context)
+        preferenceShareApp.title = getString(R.string.pref_share_app_title)
+        preferenceShareApp.setIcon(R.drawable.ic_share_24dp)
+        preferenceShareApp.summary = getString(R.string.pref_share_app_summary)
+        preferenceShareApp.setOnPreferenceClickListener {
+            val shareIntent = Intent().apply {
+                action = Intent.ACTION_SEND
+                type = "text/plain"
+                putExtra(Intent.EXTRA_SUBJECT, context.getString(R.string.app_name))
+                putExtra(Intent.EXTRA_TEXT, getString(R.string.pref_share_app_share_text))
+            }
+            startActivity(shareIntent)
+            if (!isAndroidTV && isPermissionGranted(activity as Context, android.Manifest.permission.POST_NOTIFICATIONS)) {
+                NotificationSys.showNotification(
+                    context,
+                    getString(R.string.pref_share_app_thank_title),
+                    getString(R.string.pref_share_app_thank_message)
+                )
+            }
+            return@setOnPreferenceClickListener true
+        }
 
         // set preference categories
         val preferenceCategoryGeneral = PreferenceCategory(activity as Context)
@@ -384,10 +441,13 @@ class SettingsFragment : PreferenceFragmentCompat(), YesNoDialog.YesNoDialogList
 
         // setup preference screen
         screen.addPreference(preferenceAppVersion)
+        screen.addPreference(preferenceShareApp)
 
         screen.addPreference(preferenceCategoryGeneral)
         preferenceCategoryGeneral.addPreference(preferenceThemeSelection)
         preferenceCategoryGeneral.addPreference(preferenceLanguageSelection)
+        preferenceCategoryGeneral.addPreference(preferenceCustomThemeEnabled)
+        preferenceCategoryGeneral.addPreference(preferenceCustomTheme)
 
         if (!isAndroidTV && isPermissionGranted(activity as Context, android.Manifest.permission.POST_NOTIFICATIONS)) {
             preferenceCategoryGeneral.addPreference(preferenceTestNotification)

app/src/main/java/com/michatec/radio/dialogs/LanguageSelectionDialog.kt

@@ -39,6 +39,7 @@ class LanguageSelectionDialog(private var languageSelectionDialogListener: Langu
         Language("de", R.string.pref_language_de),
         Language("fr", R.string.pref_language_fr),
         Language("ru", R.string.pref_language_ru),
+        Language("uk", R.string.pref_language_uk),
         Language("ja", R.string.pref_language_ja),
         Language("nl", R.string.pref_language_nl),
         Language("pl", R.string.pref_language_pl),

app/src/main/java/com/michatec/radio/helpers/PreferencesHelper.kt

@@ -4,12 +4,14 @@ import android.content.Context
 import android.content.SharedPreferences
 import android.content.pm.PackageManager
 import android.util.Log
+import android.util.TypedValue
 import androidx.core.content.edit
 import androidx.preference.PreferenceManager
 import com.google.gson.Gson
 import com.michatec.radio.Keys
 import com.michatec.radio.ui.PlayerState
-import java.util.*
+import java.util.Calendar
+import java.util.Date
 
 
 /*
@@ -362,4 +364,33 @@ object PreferencesHelper {
         }
     }
 
+    /* Loads custom theme color */
+    fun loadCustomThemeColor(context: Context): Int {
+        val typedValue = TypedValue()
+        context.theme.resolveAttribute(android.R.attr.colorBackground, typedValue, true)
+        return sharedPreferences.getInt(Keys.PREF_CUSTOM_THEME_COLOR, typedValue.data)
+    }
+
+    /* Saves custom theme color */
+    fun saveCustomThemeColor(color: Int) {
+        sharedPreferences.edit { putInt(Keys.PREF_CUSTOM_THEME_COLOR, color) }
+    }
+
+    /* Loads custom theme index (predefined color index) */
+    fun loadCustomThemeIndex(): Int {
+        return sharedPreferences.getInt(Keys.PREF_CUSTOM_THEME_INDEX, -1)
+    }
+
+    /* Saves custom theme color and index together */
+    fun saveCustomTheme(color: Int, index: Int) {
+        sharedPreferences.edit {
+            putInt(Keys.PREF_CUSTOM_THEME_COLOR, color)
+            putInt(Keys.PREF_CUSTOM_THEME_INDEX, index)
+        }
+    }
+
+    /* Loads whether custom theme is enabled */
+    fun loadCustomThemeEnabled(): Boolean {
+        return sharedPreferences.getBoolean(Keys.PREF_CUSTOM_THEME_ENABLED, false)
+    }
 }

app/src/main/java/com/michatec/radio/helpers/ThemeHelper.kt

@@ -0,0 +1,40 @@
+package com.michatec.radio.helpers
+
+import android.content.Context
+import android.content.res.Configuration
+import androidx.core.graphics.toColorInt
+
+object ThemeHelper {
+    fun getPredefinedColors(context: Context): List<Int> {
+        val isDarkMode = (context.resources.configuration.uiMode and Configuration.UI_MODE_NIGHT_MASK) == Configuration.UI_MODE_NIGHT_YES
+        return if (isDarkMode) {
+            // Darker colors for dark mode background
+            listOf(
+                "#FF1D3E66".toColorInt(), // Default Dark
+                "#FF3E1D1D".toColorInt(), // Red Dark
+                "#FF1D3E3E".toColorInt(), // Teal Dark
+                "#FF3E1D2E".toColorInt(), // Pink Dark
+                "#FF001A33".toColorInt(), // Dark Blue Dark
+                "#FF1D3E1D".toColorInt(), // Green Dark
+                "#FF3E2E1D".toColorInt(), // Orange Dark
+                "#FF2E1D1D".toColorInt(), // Brown Dark
+                "#FF1D242E".toColorInt(), // Blue Grey Dark
+                "#FF000000".toColorInt()  // Black
+            )
+        } else {
+            // Lighter colors for light mode background
+            listOf(
+                "#FFDAE2FF".toColorInt(), // Light Default
+                "#FFFF897D".toColorInt(), // Light Red
+                "#FF4DB6AC".toColorInt(), // Light Teal
+                "#FFF48FB1".toColorInt(), // Light Pink
+                "#FF90CAF9".toColorInt(), // Light Blue
+                "#FFA5D6A7".toColorInt(), // Light Green
+                "#FFFFAB91".toColorInt(), // Light Orange
+                "#FFBCAAA4".toColorInt(), // Light Brown
+                "#FFB0BEC5".toColorInt(), // Light Blue Grey
+                "#FFFFFFFF".toColorInt()  // White
+            )
+        }
+    }
+}

app/src/main/java/com/michatec/radio/ui/LayoutHolder.kt

@@ -6,7 +6,6 @@ import android.content.Context
 import android.content.Intent
 import android.content.pm.PackageManager
 import android.graphics.drawable.AnimatedVectorDrawable
-import java.util.Locale
 import android.view.View
 import android.view.animation.Animation
 import android.view.animation.AnimationUtils
@@ -31,7 +30,9 @@ import com.michatec.radio.core.Station
 import com.michatec.radio.helpers.DateTimeHelper
 import com.michatec.radio.helpers.ImageHelper
 import com.michatec.radio.helpers.PreferencesHelper
+import com.michatec.radio.helpers.ThemeHelper
 import com.michatec.radio.helpers.UiHelper
+import java.util.Locale
 
 
 /*
@@ -122,6 +123,9 @@ data class LayoutHolder(var rootView: View) {
             CastButtonFactory.setUpMediaRouteButton(rootView.context, it)
         }
 
+        // Apply custom theme color
+        applyCustomTheme(rootView.context)
+
         // set layout for player
         setupBottomSheet()
     }
@@ -182,6 +186,9 @@ data class LayoutHolder(var rootView: View) {
         // update bitrate
         sheetBitrateView?.text = bitrateText
 
+        // update custom theme
+        applyCustomTheme(context)
+
         // update click listeners
         sheetStreamingLinkHeadline?.setOnClickListener {
             copyToClipboard(
@@ -309,6 +316,28 @@ data class LayoutHolder(var rootView: View) {
         isBuffering = buffering
     }
 
+    /* Applies custom theme color to the UI */
+    fun applyCustomTheme(context: Context) {
+        val enabled = PreferencesHelper.loadCustomThemeEnabled()
+        if (enabled) {
+            var customColor = PreferencesHelper.loadCustomThemeColor(context)
+            val index = PreferencesHelper.loadCustomThemeIndex()
+            
+            if (index != -1) {
+                val colors = ThemeHelper.getPredefinedColors(context)
+                if (index < colors.size) {
+                    customColor = colors[index]
+                }
+            }
+
+            rootView.setBackgroundColor(customColor)
+            recyclerView.setBackgroundColor(customColor)
+        } else {
+            rootView.setBackgroundResource(android.R.color.transparent)
+            recyclerView.setBackgroundResource(android.R.color.transparent)
+        }
+    }
+
     /* Toggles visibility of the download progress indicator */
     fun toggleDownloadProgressIndicator() {
         when (PreferencesHelper.loadActiveDownloads()) {