Show jumping is a bit more relaxed than the hunters, but the expectation is still a neat, tidy and understated look. Here are the rules from USEF:
USEF Rule JP111.9.a. Formal Jumper Attire:
"Dark, muted or similar colored, or red (scarlet) coats are required; team or sponsored coats of different colors are also permitted; white or fawn breeches; a white tie, choker (unless the shirt, by design, has the chocker built in for its intended use) or hunting stock, and a white or lightly colored shirt must be worn. Shirts must have a white collar and white cuffs. Shirts must be fastened at the neck and tucked into breeches. Boots are required. Half chaps are permitted as long as the color matches the paddock boots being worn. Members of the Armed Services or the police may wear the service dress uniform with protective headgear [in accordance with GR801.2].”
USEF Rule JP1113.9.b. Proper Jumping Attire
"Coats of any color are required. Breeches must be light color (white, fawn or canary). Pastel and dark colored breeches are not allowed. Shirts, light in color, must be tucked into breeches and fastened at the top of the neck. Ties or chokers of any color must be worn (unless the shirt, by design, has the choker built in for its intended use). Boots are required. Half chaps are permitted as long as the color matches the paddock boots being worn."
What does it all mean? It means you can be a bit more creative with colors and choose among coats in navy, black, green, brown or grey, but we advise you to keep the colors conservative and make sure they compliment your partner’s color (the horse of course).
Stick with tan or white breeches are the and black or brown field boots (or half chaps) with spurs if you need them, a white or light colored shirt and a belt that compliments your look.
Protective vests designed for equestrian use are allowed for all riders.