You can select from four schemes:
Default: The Default scheme has a variety of colors schemes to choose from, and displays the Nav Bar, Full Folder List, Main Menu, and two columns with panels.
GroupWise 6.5: The GroupWise 6.5 scheme has a single color scheme and displays the Folder List, Main Toolbar, and Item List.
Simplified: The Simplified scheme has a variety of color schemes to choose from and displays the Nav Bar, Simple Folder List, and two columns with panels.
Custom: The Custom scheme allows you to set the appearance settings however you like. If you edit one of the predefined schemes, those settings become your Custom scheme.
To select a scheme:
Click Tools > Options.
Double-click Environment, and then click the Appearance tab.
Select a scheme from the Schemes drop-down list.
Click OK, and then click Close.