Camera Filter Question

Looking at some biking video I took today (a mostly cloudy day), everything seems really washed out compared to the way my camera used to film. I've had a UV filter on it since I bought it a couple years ago and it so far had seemed to film things pretty well, even in sunny/snowy conditions. Although the last time I shot video, the colors didn't seem quite as good as they normally were.

Do filters go bad or is my camera just fucked up? I noticed that it was all hazy this morning and I wiped the outside of it off, is that bad? Should I have something other than a UV filter?