MetroRadiance

PM> Install-Package MetroRadiance

using MetroRadiance.Interop;

// Get system dpi
var systemDpi = window.GetSystemDpi();

if (PerMonitorDpi.IsSupported)
{
    // Get monitor dpi.
    var hwndSource = (HwndSource)PresentationSource.FromVisual(this);
    var monitorDpi = hwndSource.GetDpi();
}

using MetroRadiance.Platform;

// Get Windows accent color
var color = WindowsTheme.GetAccentColor();

// Subscribe accent color change event from Windows theme.
var disposable = WindowsTheme.RegisterAccentColorListener(color =>
{
    // apply color to your app.
});

// Unsubscribe color change event.
disposable.Dispose();

using MetroRadiance.Media;

// Get Windows accent color (using MetroRadiance.Platform;)
var rgbColor = WindowsTheme.GetAccentColor();

// Convert from RGB to HSV color.
var hsvColor = rgbColor.ToHsv();
hsvColor.V *= 0.8;

// Convert from HSV to RGB color.
var newColor = hsvColor.ToRgb();

<Window xmlns:chrome="http://schemes.grabacr.net/winfx/2014/chrome">
    <chrome:WindowChrome.Instance>
        <chrome:WindowChrome />
    </chrome:WindowChrome.Instance>
</Window>

<Window xmlns:chrome="http://schemes.grabacr.net/winfx/2014/chrome">
    <chrome:WindowChrome.Instance>
        <chrome:WindowChrome>
            <chrome:WindowChrome.Top>
                <Border Background="DarkRed"
                        Padding="24,3"
                        Margin="8,0"
                        HorizontalAlignment="Right">
                    <TextBlock Text="any UI elements"
                               Foreground="White" />
                </Border>
            </chrome:WindowChrome.Top>
        </chrome:WindowChrome>
    </chrome:WindowChrome.Instance>
</Window>

// Change theme.
ThemeService.Current.ChangeTheme(Theme.Dark);

// Change theme (sync Windows)
ThemeService.Current.ChangeTheme(Theme.Windows);

// Change Accent
ThemeService.Current.ChangeAccent(Accent.Blue);

// Change accent (sync Windows)
ThemeService.Current.ChangeAccent(Accent.Windows);

// Change accent (from RGB Color)
var accent = Colors.Red.ToAccent();
ThemeService.Current.ChangeAccent(accent);