going to show in both hunters,jumpers & dressage.Is a black jacket good for all three or is navy better in the hunter ring?
Black is grood anywhere though Dressage has some minor style differences with buttons. Don’t see many jackets in Jumpers unless formal attire is requested or expected. Like in a $$$$ Classic or GP. Blue is the traditional choice in Hunters but any dark, conservative color is safe. If a rider has a reputation for laying down 88+ trips, they can wear whatever they want in the Hunters.
Equitation would be dark blue and have seen black.
You’re fine in a black coat for all three; you see more color in dressage now though, so if you prefer navy that’s totally acceptable. I showed at a recognized dressage shows for two days last month in my navy coat.
Most of the jackets now are made to be used in whatever ring, most of the stylistic differences of the past are a thing of the past. AND they can go in the washing machine!
Fashion-trends-wise, navy might be preferred, but black is always correct in hunters, as the sport evolved from fox hunting where we wear black jackets.
They have been wearing navy in dressage since at least the mid-1970s when I was showing and its always been appropriate for hunters so I think that would be your best bet but black is just as correct. They hardly wear jackets in the jumpers now except for the big classes but you can’t go wrong with either color in any ring.