My initial opinion when I first read the play I thought Claudius was a very dark character, he silences everyone around him like in the speech about his brother, no one talks unless they are told directly, which I guess is how people are meant to react around a king but when Claudius speaks it is very coldly and the things he talks about his old brother being dead and that Hamlet should get over it. There isn't any emphasis in his lines, that is mostly my own bias though. I thought he was cold and dark because he speaks about a delicate subject and just talks like it means absolutely nothing to him.
The films we watched influenced my thoughts a lot. Watching Claudius played differently made me see him in different lights, there was a dark nasty character and a nice normal king. This has now changed what I think about Claudius because I have seen him in these different lights.