As I mentioned in an other thread:
Colors are a matter of taste.
But it's not like that i've made a forum theme with dark grey fonts on a black background.
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Right now it's not only black on white but also green on grey, black on light blue (quote), grey on light grey,
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light green on light grey (links),etc.
I tried to keep the 'readability' high. Maybe the topic links could use a bit more contrast but I'm using the theme right now and I think it's still extreme readable (at least for me).
If you don't like the colors, that's another point.
My intention was not to dictate a look, but to offer a choice.