The subculture of hound hunt packs extends to attire.
The livery for the Masters and hunt staff of Harrier packs in the UK is traditionally green coats (as opposed to the scarlet coats one sees with Foxhounds), though some Harrier packs do indeed wear the scarlet, probably because somewhere in the pack’s long history, a member of the royal family hunted with their pack, and as a compliment to the hunt, s/he granted them the right to wear the scarlet. To that end, we were given a handy rule of thumb: The color of the coat generally signifies the type of hound being hunted. When looking at paintings of hunt scenes, if the name of the pack isn’t recognized (assuming one is given), and if the participants are mounted and wearing green coats, the hounds are Harriers (or Beagles). Scarlet is always worn with foxhounds, while those hunting with Bassets on foot normally wear blue.
Attire etiquette extends to finer details: The number of buttons, a stock pin worn vertically or horizontally, number of buttons (a Master who hunts hounds should have five buttons, but there should also be two hunt buttons on the back of the coat if it is a frock coat, and two or three small buttons on the cuff of each sleeve). The material should be twill or Melton cloth, and, well, you get the idea. Proper attire covers boots, crops, hat, vest, breeches, and gloves.
Image of the Dunston Harriers in East Anglia courtesy of Donna Smiley