I am doing the same thing I always do. I am working in RGB mode, as I always do. When I go to save a graphic or picture, though (but this doesn't happen with photos from my camera), the colors it saves as are much more muted than the original. They aren't nearly as vibrant. I've tried saving as all sorts of different file types (jpg, gif, png, etc), all on the maximum settings.
Here's an example:
Original on the left.
If you don't know or don't care,
[edit: in b4 grammar police]