Mark Todd, Equestrian Rider, age 52.
The red competitor is called "hong" (홍) The blue competitor is called "chung" (청)
The term"equestrian" is used for anyone who rides.
an equestrian.
Opponent
KP Equestrian
KP equestrian.
Ringmaster, ringleader or Equestrian Director
Yes, it is called horse ball.
He/She is called competitor or participant.
A female equestrian is typically referred to as a "horsewoman" or "equestrienne."
The person who rides a horse would be called either a equestrian or horse rider, but if the person only rides in shows, they may also be called show riders.