hope u will help me out

i am developing a site using phpnuke 7.0 version.
what problem is....i have leftside menus areas, center box areas and right side menus areas (as nuke default theme).....
but i want different colors in leftside (marron),center(light green) and rightside(green)....

how can i do that?

expecting quick reply from you.

thanks and regards
ravera