Reference guide to the css styles I can use on tabs (and other widgets)?

Greg Brown​ TWX Studio provides styling in either Ionic (style classes) or manual CSS i.e., for a widget or a resource we can provide the Ionic class which will automatically changes the styles or define styles based on the class names.

For ionic style classnames, follow the ionic cheatsheet - Ionicons v2.0.0 Cheatsheet​ , also there are class names like 'button-dark' that turns the color of the button into black, button-calm (light-blue), button-balanced (green) etc.,