So many of us agree that the new not-black topbar looks awful on Physics.SE. One solution to this would be to change the top-bar to reduce the discord, as has been done on scifi.SE and askubuntu.com (and possibly other sites).
However, another possibility would be to rethink the design of Physics.SE itself. Personally, I find the current design a little uninspiring anyway, and since many of the other Stack Exchange sites have really excellent designs I was wondering if it might be time to give ours another look.
I'm not a design expert, but I've never been a fan of the colour scheme, which somehow seems to say "company that makes elastic bands or something" rather than "community of academic experts and enthusiasts". Since one of the main problems with the top bar is the clash between the Stack Exchange logo and the main colours of our site, perhaps this would be a good time to think about changing our colour scheme. If we could also have a more modern-looking design with some (off-)black elements rather than just light blues and greens then the top bar might not look out of place at all.
I have no idea how likely this is to happen, but I thought it might be worth putting the idea out there to see if it gets any reaction from Stack Exchange and/or the community.
It really wouldn't require a big change. The following is not a serious suggestion (as I said I'm no designer) but here is the result of spending a couple of minutes applying colour curves in GIMP, to reduce the amount of green and red in the colour scheme, while leaving the top bar untouched:
As you can see the colour clash against the Stack Exchange logo is greatly reduced, and the overall darker colour scheme lessens the impact of the bar itself. A proper designer could do a much better job, but the point is that a few gentle tweaks could make it look a lot less bad.