The colours look "lacking" and ever slightly blueish and rather washed-out and lacking in dimension.
Graphics are ok - this page for example looks fine - but if I view something like a news site with high quality photos, the experience is not optimal and is noticeably inferior to Windows 7.
Oddly, when I install Ubuntu as a VM on VirtualBox in Windows, the colours look as I expect them to. It's only on my dual-boot version of Ubuntu that they look wrong (not Wubi, although a previous Wubi-based installation had the same problem).
Now, I have the proprietary ATI driver and I can use amdcccle to get the colours closer to what they should be, but I can't seem to do anything about colour depth.
The depth settings in Xorg are all 24. I tried changing all three mentions of 24 to 32 but was forced into safety mode. Fortunately, I remembered where I'd been tinkering and got the file set back to 24.