If you’ve upgraded to Ubuntu 11.10, you may have noticed your movie files not looking as they should in the default Movie Player (Totem), and probably others like SMPlayer and MPlayer. For me, the clips actually looked fine first off, but only in Totem, as SMPlayer kept crashing. Then, after getting some updates, Totem started displaying the colours all mixed up (as did SMPlayer, which wasn’t crashing any more). I tested GNOME MPlayer, and that was fine, but all my other players were affected.
From the looks of comments I’ve seen around, updating/installing Medibuntu is a likely suspect, but whatever the cause, it should actually be quite easy to fix. Simply go to Edit > Preferences > Display in Totem, and adjust the Hue from the default 50% mark all the way up to 100%. If yours is all the way down at 0%, as some have reported, then you definitely need to do the same. You may need to do this with each player, but in my case changing the setting in Totem immediately rectified the problem in SMPlayer. If it doesn’t for you, however, then you know how to fix this easily.
Lastly, don’t be surprised if later on you go to play a vid and your colours are all mucked up again. This time, you’ll probably find the Hue is still at 100%, so you’ll need to drop it back to the default of 50%. It might be a bit of a hassle, but this should be fixed up at the development end soon enough, and at least it only takes a few seconds to get your movies looking as they should.