I've only tried blue so I'm not really sure. I'm looking to get a cherry red keyboard though.
But I heard pretty good and bad things about brown switches. Seems like the people who likes it really loves it but the people who hates it despises it.
But I think the only real difference between them is the tactile feeling though. Reds are linear switches which doesn't have that tactile bump so it can feel weird for some people.
So it's really up to personal preferences which one you'd like. I recommend going to a store and try them out for yourself to see which on you like better.