beige/greenish beige breeches with a light shirt and darker jacket (greys, navys, some browns) are traditional for the hunt ring. Subtle (and some not so subtle) changes come in and out though. Rust breeches started coming in last year (mainly rated shows) but I haven't seen as many lately. My friend who runs a tack shop told me black jackets (with a subtle pinstripe or plaid) were coming in and at the Syracuse Invitational almost everyone had a black jacket. And Euroseat breeches (kind of look like full seat breeches, but also have knee patches). Show jackets with colored piping around the collar are getting to be popular as well. I've noticed with the jumpers people are getting jackets with colored collars. I think the piping is cool but colored collars are too much for me. For a while GPA and Charles Owen helmets were neck and neck but I think CO's are finally winning out. (at least in certain parts of the country) GPA Speed Airs are still pretty popular though.
All my show breeches are greenish beige. My jacket is a charcoal grey with some plaid. I have a light blue plaid, pink plaid, lavender, khaki/white, and green striped show shirt.