I'd love to get a dark theme in my foobar, but it just seems like a lot to figure out at the moment. I guess I'd have to make my own toolbars with play buttons etc, etc, etc. I'm aware there are themes, though. Maybe someone's done something I can build on.
I actually went back and removed all my extra foobar2000 components and reverted back to the default playlist. I realized I cared more about the music being played and less about how the player looked.
Cadrian, since you have a sizeable collection, you should take a look at Winamp's Smart View function if you haven't. Just look at the left, you can right-click f.ex "Audio" and then choose "New Smart View" or something along those lines. You can set up filters or "queries" for how you want to access your music.
It's pretty easy to figure out and let's you find stuff a little easier.
Also when you have a large library, the search bar from Winamp is quite handy as scrolling doesn't work very well - you know what I mean. I love the fact that the winamp search also searches for stuff included in path/filename (although searches in big libraries are a bit slow). You can get the same functionality for Foobar, for example the Columns UI panel Quicksearch Panel.
You can see that searchbox here in my screenshot at the top of my foobar with a light red background coloration.
The smart view functionality in Winamp, should you come to like it, is also easily replicated in Winamp, also demonstrated in the screenie on the left hand side.