Theme Engine

PleasantUI ships 10 built-in themes, a System mode that follows the OS, and a full custom theme editor with create/edit/export/import support.

Built-in themes

Light, Dark, Mint, Strawberry, Ice, Sunny, Spruce, Cherry, Cave, Lunar, System

Switching theme in code

// Switch to a built-in theme by name
var theme = PleasantTheme.Themes.First(t => t.Name == "Dark");
PleasantSettings.Current!.Theme = theme.ThemeVariant;

Binding a theme selector in AXAML

<ComboBox ItemsSource="{x:Static PleasantTheme.Themes}"
          SelectedItem="{Binding SelectedTheme}">
    <ComboBox.ItemTemplate>
        <DataTemplate DataType="models:Theme">
            <TextBlock Text="{Localize {CompiledBinding Name}, Context=Theme}" />
        </DataTemplate>
    </ComboBox.ItemTemplate>
</ComboBox>

Custom themes

Creating programmatically

var colors = PleasantTheme.GetThemeTemplateDictionary(); // start from Light
colors["AccentColor"] = Color.Parse("#FF6B35");          // override accent

var custom = new CustomTheme
{
    Name   = "My Theme",
    Colors = colors.ToColorPalette()
};

PleasantTheme.CustomThemes.Add(custom);
PleasantTheme.SelectedCustomTheme = custom;

Using the built-in editor

// Open the theme editor window (from PleasantUI.ToolKit)
CustomTheme? result = await ThemeEditorWindow.EditTheme(window, existingTheme);
if (result is not null)
    PleasantTheme.CustomThemes.Add(result);

Editing an existing custom theme

CustomTheme? updated = await ThemeEditorWindow.EditTheme(window, myTheme);
if (updated is not null)
    PleasantTheme.EditCustomTheme(myTheme, updated);

Accent color

The accent color is automatically derived from the OS accent on Windows/macOS, or can be set manually:

PleasantSettings.Current!.NumericalAccentColor = 0xFF6B35FF; // ARGB
PleasantSettings.Current!.PreferUserAccentColor = true;

Light/dark accent variants (AccentLightColor1–AccentLightColor3, AccentDarkColor1–AccentDarkColor3) and gradient brushes are generated automatically.

Settings persistence

PleasantSettings is loaded from and saved to disk automatically on desktop. The settings file lives at:

%AppData%/[AppName]/Settings/Settings.json   (Windows)
~/.config/[AppName]/Settings/Settings.json   (Linux/macOS)

Key settings:

Setting	Description
Theme	Active ThemeVariant
NumericalAccentColor	User accent color (ARGB int)
PreferUserAccentColor	Use user color instead of OS accent
CustomThemeId	ID of the active custom theme
WindowSettings.EnableBlur	Global blur toggle
WindowSettings.EnableCustomTitleBar	Global custom title bar toggle
WindowSettings.OpacityLevel	Background opacity (0–1)

Color tokens

All theme colors are exposed as DynamicResource keys:

Key	Usage
BackgroundColor1–4	Window/panel backgrounds (lightest to darkest)
ControlFillColor1–3	Control fill states (normal, hover, pressed)
TextFillColor1–3	Text (primary, secondary, disabled)
AccentColor	Primary accent
AccentLightColor1–3	Lighter accent variants
AccentLinearGradientBrush	Gradient brush for accent buttons
ControlBorderColor	Default border color
SystemFillColorCritical	Error red
SystemFillColorSuccess	Success green
SystemFillColorCaution	Warning yellow
DangerColor	Danger button background