To the right of a Team Name is a square of Team Color. This color will be displayed as background around a team's name & score box during game play:
To manipulate these colors, click on a color square:
You may either select a color box from the Preset Colors on the top of the screen, or you can Adjust RGB Values to customize your own Team Colors.
Click OK to use the color that you've made or Cancel to exit the Color Selector.