how to change font of  title text?

I know that as described here:
https://github.com/jaredrummler/ColorPicker/issues/73
I can change the style of select button as 
        <item name="buttonBarPositiveButtonStyle">@style/BtnStyle</item>
and preset/custom button as 
        <item name="buttonBarButtonStyle">@style/BtnStyle</item>
but how to change title style?
