With Recent Flash upgrade to version 10.2, I faced a a strange issue with regarding to playing videos on youtube. all video I played on main site or yourtube video embedded in other sites like facebook were in red color, while the audio was playing just fine. something like in screenshot below:
It turns out that this is a bug in Adobe Flash Player 10.2 introduced because adobe enabled hardware acceleration to for all users, but in case hw accel does not work properly. video will appear in weird colors. while adbobe is working on the bugfix, the current workaround is to disable Hardware acceleration.