I feel a bit stupid but is Stephen Colbert conservative, liberal or independent? I really can't tell.?

He is an actor but politically he comes from the Liberal spectrum of the Catholic Church. Don't conflate Liberal with being a Democrat even though he is a Democrat. It is simply that the Liberal spectrum of the Catholic Church supports the Democrats at this time, that doesn't mean they always will.

Liberal, far left liberal.

After watching him, when you come away with a sense of conservatives/Republican/Tea Party people really are the worse and that Democrats/Obama/Pelosi/Clinton/Biden aren't really that bad, yeah, that's because he just successfully left an impression upon you to side left. It's called brainwashing, and he's probably pretty good at it considering the number of liberals there are who can't tolerate anything that disagrees with the left.

Although, since he's been selected to replace Letterman, Colbert may be wanting to show that he can joke about either side more now. I mean the Late Show is not left-wing-only show. A lot of people from all over the political spectrum like to watch shows like that.

Can you imagine a far-left talk show host like Colbert taking over the Late Show, and because he's so far left, that like a 3rd or more of their rating suddenly drop?

Yeah, that's probably what's going on here. He's trying to prove that he doesn't have to just be left-wing. But then, it's always a show with liberals. Even if it seems he's remaining neutral, I guarantee he's making the left look better as much as he can. I've rarely seen a liberal who can be neutral. It's always an act where the left is usually touted as the better of the two evils or as if they simply have better ideas.