While the new theme is pretty nice, over the last couple days I've spotted a couple usability issues stemming from the design itself.
Most notably, I'm having trouble spotting the difference between controls that are ticked and those that are not. The most glaring one is the up/down vote controls on meta. On several systems I work on the shade difference is subtle enough that I've caught myself clicking the vote controls again because I couldn't see that I already had. On a couple better monitors the difference is clearly distinguishable — until the sun glares off the wall behind me and then suddenly I can't tell what I've voted on any more.
While this is mostly obviously a problem on meta, I just hit a vote button on main too. The difference is just not noticeable enough that understanding the selection state is second nature.
Could the color scheme for both sites (but particularly meta) be darkened up a shade or two to improve usability on monitors with poor rendering or bad lighting situations?