Color Manager
The color manger should help you to configure the colors of TWG as good as possible. You can use the Color Picker to find the RGB values you need for the configuration files. You can also select a color and click on the left side and make a nice layout. The created style sheet should be stored as skin or my_style.css as a template. If you want to change any font sizes please use the template as starting point because all areas that make sense to change are in this template.
If you want to change the color of the iframes please edit the i_frame/iframe.css