ColorThemeChangeEventArgs.ColorTheme

public ColorTheme ColorTheme {get;}

colorThemeChangeEventArgs.ColorTheme: ColorTheme

protected override void OnStart()
{
    Application.ColorThemeChanged += OnColorThemeChanged;
}

private void OnColorThemeChanged(ColorThemeChangeEventArgs args)
{
    var textColor = args.ColorTheme == ColorTheme.Dark ? Color.White : Color.Black;
    Chart.DrawStaticText("theme", "Theme: " + args.ColorTheme, VerticalAlignment.Top, HorizontalAlignment.Right, textColor);
}

def on_start(self):
    api.Application.ColorThemeChanged += self.on_color_theme_changed

def on_color_theme_changed(self, args):
    text_color = Color.White if args.ColorTheme == ColorTheme.Dark else Color.Black
    api.Chart.DrawStaticText("theme", f"Theme: {args.ColorTheme}", VerticalAlignment.Top, HorizontalAlignment.Right, text_color)