Cannot change the background color of my entire theme

Hi there: I am a newbie, and am trying to change the background color of my theme – which is Flatee by Themes4all. It’s an off-white background with red background on banner navigation and such. I just want to change the off-white to white. I’ve tried setting background to white and it changes the top banner navigation.

the staging site is staging2.mscheevious.com

Please let me know. Many thanks!