[napy8gen]

Goto stylemanager> stylename> main CSS> Category Strips>

by default it has a background image repeating itself horizontally.

In the background property.default style have like this :

#869BBF url(images/gradients/gradient_tcat.gif) repeat-x top left

you can change this to no-repeat :

#869BBF url(images/gradients/gradient_tcat.gif) no-repeat top left

change the image path to your image. and color to your right area after the image on the left .

if the category text now overlapping with your left image.
just put in the additional css attributes box in the category strips css panel this value,

padding-left:40px;