The body text is #444 which is hard on the eyes. Stackoverflow.com uses black, easy to read. How about either allowing preferences (hard), or just color the text black (easy) so it is easier to read?
I have darkened the text, please let me know if it's better for you. I didn't use a pure black on white treatment because it's a bit too harsh on the eye in my experience dealing with users. (of course monitors' gamma can vary quite a bit).