right:
in the replacements section of your admin cp edit the { categorybackcolor} replacement:
Change the color you have in the box ... For arguements sake lets say its #000000. So change the code you have to this:
PHP Code:
#000000" background="{ imagesfolder}/gradient.gif"
Simply remove the gap between the funny bracket and the imagesfolder...
You also need to upload that gradient to your imagesfolder too.
Regards
- miSt