Changing the style in the application without app.xml

[NoobCSharp]

Hi, I have an application window in which I connect a resource dictionary containing styles. How can I change the colors for styling? I use PaletteHelper directly in window initialization and change the color, but nothing happens.

_palette Helper = new PaletteHelper();
ITheme theme = _paletteHelper.GetTheme();

Color Pair color Pair PrimaryDark = theme.PrimaryDark; //-> see color
Color Pair color Pair Primary Light = theme.Primary Light; //-> see color
Color Pair colorPairPrimaryMid = theme.PrimaryMid; //-> see color

theme.SetPrimaryColor(Colors.Red);
theme.SetSecondaryColor(theme.PrimaryLight.Color);

colorPairPrimaryDark = theme.PrimaryDark; //-> color has changed
colorPairPrimaryLight = theme.PrimaryLight; //-> color has changed
colorPairPrimaryMid = theme.PrimaryMid; //-> color has changed

_paletteHelper.SetTheme(theme); - apply theme