We already have a few posts describing the blue voting arrows. This post is about the blue text at the front page:
The blue color is way too attractive to the eye. For an exercise, try scrolling through the list looking for a particular question. I felt it burnt my eyes.
The tags use the same color as the question text, which is wrong. The tags should use a duller, less attractive color, as they do not share the same visual priority with the question text.
I find the color scheme of the meta site to be much better - the grey color renders the text comprehendible, which is most important for any website.