[fat boy]

Here ya go

Change background and highlight color in start menu in TF3D
use reg editor to go to HKLM\Software\HTC\EnlargeMenu
edit the keys for ManilaCustomHlUp and ManilaCustomHlDown to decimal number 240, 140 or 91 (that will be a dark red) to change the highlight color.
Create a png file in a graphic program sized 2pixel by 2pixel in the color you want your background, save as 24bt and name it what you want... put it in windows folder on your phone and then edit the key CustomManilaTexture to point to that file...
Then edit your registry
HKLM\Software\HTC\EnlargeMenu\CustomManilaTexture\ edit key to say \WINDOWS\pattern_2_2.png or whatever the name of the file is.

For the taskmanager drop down point the custom texture file to the same pattern_2_2.png you pointed to in the startmenu...
HKCU\Software\HTC\TaskManager\ManilaCustomTexture point to \WINDOWS\ pattern_2_2.png

If you want to make it gradiant you can put two different colors for UP and DOWN. Black works good.