Changing the color of the actual Posting and Page background in WordPress Theme 2010 was a bit of a trick. Had to mess about with it and finally found where the code goes:
The script is in Style.css and located under ‘Structure’ :-
#wrapper {
background: #fff; [ I changed this value from #fff to suit my choice ]
margin-top: 20px;
padding: 0 20px;
}
The codes for Web Colors are listed at the Wiki Site, with a full explanation of where all the codes originated and why they might appear in 3 digit fff or 6 digit FFFFFF format.
I just found the massive white space in the Default Theme too oppressive.