Exit. Surprising when using the color icon in fcpx

This is a known bug, mostly on Intel Macs. 10.7 unleashed a bunch of bugs on Intel Macs running FCPX. Yep, known bug.

Delete preferences (launch FCPX while holding both opt+cmd keys together).

Delete all render files for the Library (via File menu).

Reboot, relaunch, you should be good.