You are always allowed to participate in competitions wearing the club uniform. Military personnel, police officers, and similar may wear a participant's outfit or a uniform. Most clubs no longer have an official club uniform. Then, during the dressage test or the jumping course, as a participant, you must adhere to the following clothing requirements:
- A riding jacket resembling a blazer. The jacket must have buttons and a low-standing collar. Color is unrestricted.
- A shirt or blouse. This must have sleeves (short or long) and a high collar.
- White, beige, or yellow riding breeches. The seat and knee patches may have a different color.
- A pair of riding boots or jodhpur boots in combination with matching, smooth leather/smooth synthetic leather chaps. The color is unrestricted. The combination of stirrup and riding boot/jodhpur boot must be such that, in case of emergency, the foot can leave the stirrup unhindered.
- Wearing a safety helmet that complies with the safety standards applicable to equestrian sports is mandatory for everyone on horseback at the competition venue. A participant who loses their headgear or whose safety system comes loose must fix it, or in the case of a loose safety system, secure it.
- Gloves are not mandatory. If you choose to wear gloves, the color does not matter.
- A stock tie is not mandatory.
- From the Lichte Tour class onwards in dressage, a riding skirt may also be worn.
Furthermore, you may ride with a body protector during the competition. The body protector may be worn over or under the competition clothing. An inflatable safety vest/body protector attached to the saddle may also be used.
Source: KNHS.nl (The Netherlands)
FEI Rules:
According to the FEI guidelines for dressage competitions, riders must wear a suitable riding jacket that complies with the formal dressage clothing regulations. Generally, riders are expected to wear a black or dark blue riding jacket. The jacket must have a traditional cut, with long sleeves and a collar. Other colors than black or dark blue are not always accepted in the dressage arena at FEI competitions. During Ermelo Young Horses, all colors are allowed.
It is always advisable to consult the specific dressage regulations of the FEI and the regulations of the national federation of the respective country for any updates or additional requirements regarding riding jackets at dressage competitions.
Check www.fei.org