Hence I just set the theme to "Silver" (aka not the default of "Retina-searing blue") and left it that way forever.
Finally found one I like, though. And it's from Microsoft. And I'm apparently not supposed to have it. It's "Energy Bliss" which is included with the new Media Center 2005 edition. It's sorta halfway between silver and blue and is pretty easy on the eyes.
You can download it from MS, but it refuses to install on regular old XP. Somebody pointed out, though, that WinRAR (and PowerArchiver I discovered) will open Microsoft's exe file and will give you everything you need to install it manually.
In fact, somebody made their own little installer for it. You need to run it in safe-mode, though, for it to install completely. Once installed, though, it looks great.
Check out the Neowin discussion for all the info.