If color is your concern, here are some guidelines and some dazzling graphics. However, don't overthink color. The comments offer some sobering thoughts on the effect of color on success.
I reviewed 47 wordpress templates for a competition earlier this year. 98% of them used a "flat" design approach. Of course, we're seeing this style of design pervade websites.
Is this a good thing? Nielsen Norman Group says we can use flat designs if we follow some smart guidelines.