I did a clean install of Ubuntu 14.04 LTS. I'm having a weird problem that I can't find any mention of online. Basically, all UI elements in apps look grey, Windows 98-style.
(Firefox file upload)
Functionally everything is fine, but it just looks ugly. Unity,the desktop and the login screen look completely normal. Logging out and back in fixes the issue, but it comes back after rebooting.