Various imporvements.

* Added auto colour option for all configurable colours.
* Update AccentColourPicker to custom control.
* Added black and white colour to available colours.
* Debounced all battery status update calls to further minimise back pressure problem.

App/App.xaml.cs

@@ -4,25 +4,29 @@
 using System.Windows;
 using System.Windows.Media;
 using Wpf.Ui;
+using Wpf.Ui.Markup;
+using static Percentage.App.Properties.Settings;
 
 [assembly: ThemeInfo(ResourceDictionaryLocation.None, ResourceDictionaryLocation.SourceAssembly)]
 
 namespace Percentage.App;
 
 public partial class App
 {
-    internal const string DefaultBatteryChargingColour = "#10893E";
-    internal const string DefaultBatteryCriticalColour = "#E81123";
+    internal const string DefaultBatteryChargingColour = "#FF10893E";
+    internal const string DefaultBatteryCriticalColour = "#FFE81123";
     internal const bool DefaultBatteryCriticalNotification = true;
     internal const int DefaultBatteryCriticalNotificationValue = 10;
     internal const bool DefaultBatteryFullNotification = true;
     internal const bool DefaultBatteryHighNotification = true;
     internal const int DefaultBatteryHighNotificationValue = 80;
-    internal const string DefaultBatteryLowColour = "#CA5010";
+    internal const string DefaultBatteryLowColour = "#FFCA5010";
     internal const bool DefaultBatteryLowNotification = true;
     internal const int DefaultBatteryLowNotificationValue = 20;
-    internal const string DefaultBatteryNormalColour = null;
     internal const bool DefaultHideAtStartup = false;
+    internal const bool DefaultIsAutoBatteryChargingColour = false;
+    internal const bool DefaultIsAutoBatteryCriticalColour = false;
+    internal const bool DefaultIsAutoBatteryLowColour = false;
     internal const bool DefaultIsAutoBatteryNormalColour = true;
     internal const int DefaultRefreshSeconds = 60;
     internal const bool DefaultTrayIconFontBold = false;
@@ -38,6 +42,8 @@ public App()
     {
         _appMutex = new Mutex(true, Id, out var isNewInstance);
 
+        if (!isNewInstance) Shutdown(1);
+
         DispatcherUnhandledException += (_, e) => HandleException(e.Exception);
 
         AppDomain.CurrentDomain.UnhandledException += (_, e) => HandleException(e.ExceptionObject);
@@ -46,7 +52,8 @@ public App()
 
         InitializeComponent();
 
-        if (!isNewInstance) Shutdown(1);
+        // User settings migration for backward compatibility.
+        MigrateUserSettings();
     }
 
     internal static Exception GetTrayIconUpdateError()
@@ -97,6 +104,23 @@ internal static void SetTrayIconUpdateError(Exception e)
 
     internal static event Action<Exception> TrayIconUpdateErrorSet;
 
+    private void MigrateUserSettings()
+    {
+        if (Default.RefreshSeconds < 5) Default.RefreshSeconds = 5;
+
+        Default.BatteryNormalColour ??=
+            ((Brush)FindResource(nameof(ThemeResource.TextFillColorPrimaryBrush)))!.ToString();
+
+        if (Default.BatteryLowColour is { Length: 7 } lowColourHexValue)
+            Default.BatteryLowColour = lowColourHexValue.Insert(1, "FF");
+
+        if (Default.BatteryCriticalColour is { Length: 7 } criticalColourHexValue)
+            Default.BatteryCriticalColour = criticalColourHexValue.Insert(1, "FF");
+
+        if (Default.BatteryChargingColour is { Length: 7 } chargingColourHexValue)
+            Default.BatteryChargingColour = chargingColourHexValue.Insert(1, "FF");
+    }
+
     protected override void OnExit(ExitEventArgs e)
     {
         // Save user settings when exiting the app.

App/Controls/AccentColourPicker.cs

@@ -0,0 +1,81 @@
+using System.Windows;
+using System.Windows.Controls;
+
+namespace Percentage.App.Controls;
+
+public class AccentColourPicker : Control
+{
+    public static readonly string[] AccentBrushes =
+    [
+        "#FF000000", // Black
+        "#FFFFFFFF", // White
+        "#FFFFB900", // Gold
+        "#FFFF8C00", // Dark Orange
+        "#FFF7630C", // Orange
+        "#FFCA5010", // Burnt Orange
+        "#FFDA3B01", // Red-Orange
+        "#FFEF6950", // Salmon
+        "#FFD13438", // Red
+        "#FFFF4343", // Bright Red
+        "#FFE74856", // Light Red
+        "#FFE81123", // Crimson Red
+        "#FFEA005E", // Pink
+        "#FFC30052", // Magenta
+        "#FFE3008C", // Fuchsia
+        "#FFBF0077", // Dark Magenta
+        "#FFC239B3", // Purple
+        "#FF9A0089", // Dark Purple
+        "#FF0078D7", // Blue
+        "#FF0063B1", // Royal Blue
+        "#FF8E8CD8", // Lavender
+        "#FF6B69D6", // Indigo
+        "#FF8764B8", // Violet
+        "#FF744DA9", // Purple Indigo
+        "#FFB146C2", // Orchid
+        "#FF0099BC", // Teal
+        "#FF2D7D9A", // Peacock Blue
+        "#FF00B7C3", // Light Aqua
+        "#FF038387", // Dark Cyan
+        "#FF00CC6A", // Light Green
+        "#FF10893E", // Green
+        "#FF7A7574", // Taupe
+        "#FF5D5A58", // Dark Gray
+        "#FF68768A", // Cool Gray
+        "#FF515C6B" // Slate
+    ];
+
+    public static readonly DependencyProperty IsAutoColourProperty = DependencyProperty.Register(
+        nameof(IsAutoColour), typeof(bool), typeof(AccentColourPicker),
+        new FrameworkPropertyMetadata(false, FrameworkPropertyMetadataOptions.BindsTwoWayByDefault));
+
+    public static readonly DependencyProperty LabelProperty = DependencyProperty.Register(
+        nameof(Label), typeof(string), typeof(AccentColourPicker));
+
+    public static readonly DependencyProperty SelectedColourProperty = DependencyProperty.Register(
+        nameof(SelectedColour), typeof(object), typeof(AccentColourPicker),
+        new FrameworkPropertyMetadata(null, FrameworkPropertyMetadataOptions.BindsTwoWayByDefault));
+
+    static AccentColourPicker()
+    {
+        DefaultStyleKeyProperty.OverrideMetadata(typeof(AccentColourPicker),
+            new FrameworkPropertyMetadata(typeof(AccentColourPicker)));
+    }
+
+    public bool IsAutoColour
+    {
+        get => (bool)GetValue(IsAutoColourProperty);
+        set => SetValue(IsAutoColourProperty, value);
+    }
+
+    public string Label
+    {
+        get => (string)GetValue(LabelProperty);
+        set => SetValue(LabelProperty, value);
+    }
+
+    public object SelectedColour
+    {
+        get => GetValue(SelectedColourProperty);
+        set => SetValue(SelectedColourProperty, value);
+    }
+}