As part of theming, you may want to change the grid colors of anything that displays a paginated view, such as Users, Announcements, Help Desk, or Expense Reports. The islands look similar to the one below:
These items are changed in the PortalGrid.skin file in the App_Themes folder.
Lines 1 and 3 are affected by:
<PagerStyle BackColor="#6487DB" ForeColor="White" />
Line 2 is affected by:
<HeaderStyle BackColor="#D8E1F8" Font-Bold="false" ForeColor="Black" HorizontalAlign="Left" />