I'm trying to figure out what to do with my ND filters. I'm using the Cokin 'P' series holder and filters right now (both ND and gradient ND) but I've noticed a bit of a color cast on them (kind of an orange color.) I love the square holder for the gradient but would rather not have a color cast. Looking around it looks like some people say it's fixed by adjusting the WB but I'd rather have ND filters that are truly neutral. Sounds like my options are to either deal with it, get better screw in filters and just use the Cokin for gradient stuff, or get better filters to go into the Cokin holders. I hear Lee filters are the best but they're super spendy. I guess Hi-tech(?) are good also but the only place I saw that carried them was a UK company. What's the best way to go?