Someone help me with CSS overriders please

This is my second post about this .... Please help me with CSS overrides to allow me change the background and foreground color of pages and the horizontal bar on top of the page.... Someone help please else just tell me which CSS file to edit for these.

Also, my main menu seems to have some problem... can someone look-into this please. My website is www.socialite.in

Please don't double posts.