I'm sure I didn't change anything, but the background for the post div "main" (as well as "center") is the default theme color 3f4c6b. Of course it should be white. The weird thing is that in pages, these divs show white correctly...
The only way I see to change this is in style1.css background but that changes the theme colors on the home page as well.
I haven't changed any of the theme color scheme at all so I'm not sure why this is happening. I'd so much appreciate your insight!