[cloudywool]

i m using 4.2 and this is how it worked for me, altho the bg color i changed to was ugly and i changed it back later. if you want to change the look just changing the bg color isnt enough, u got to create a whole new theme to look consistent, anyways.
this is how i changed bg:
locate skin1/main.css
copy paste main.css in text edit
command+F(in mac) to locate code"#ffffff" then replace all "#ffffff" with the color you want(because the css was too long and i wasnt entirely sure which #ffffff is in charge of the main bg so i just changed them all, a dumb method i'd say, but works)
paste the new main.css in skin1/main.css and save
reset safari or other browsers clean up the old data
load your site again and the bg should be changed(most likely to be ugly tho cause changing only one thing in a while design usually look weird)

MUST BACK UP YOUR MAIN.CSS BEFORE YOU EDIT IT, IN CASE YOU HATE THE NEW COLOR SO YOU CAN CHANGE IT BACK.