Log in to the Portal Server administration console.
Edit the display profile for the Developer Sample organization.
To edit the display profile:
Select Global Themes and the theme you wish to modify in the DP XML Tree.
Change the value of the titleBarColor property to change the color of the selected tab and/or change the value of tabColor property to change the color of an unselected tab.
The selected tab background color is the same as the title bar color.
Reload the Desktop to verify the change.