When Ping manufactures golf clubs, irons in particular, they mark the clubs with colored dots that represent the angle of the club head to the standard shaft angle. The two important measurements are height of the golfer and distance from the ground to the player's wrists when he is standing naturally.
A player who has longer arms relative to his height needs a shaft that extends out from the club at an angle closer to the ground than a player of the same height with relatively short arms. The golfer's height and wrist measurements are then compared with the Ping color chart, which the pro shop selling the clubs should have, to find the ideal color.
The fitter begins the fitting process by interviewing the golfer to determine his swing problems, club needs and other information about his game. The fitter also takes a hand measurement to determine the proper grip size and conducts a swing test in which the golfer hits a few balls off of an impact board. The board has special tape on which the club's sole leaves a mark. The mark's placement helps the fitter better understand the golfer's setup and swing; the fitter can make adjustments in the club choice if needed.
The standard dot color is black. Blue dot clubs have 0.75 degree more upright hosels than black dot clubs, followed by yellow, green, white, silver and maroon, with an additional 0.75 degree more upright at each level. That means maroon clubs are 4.5 degrees more upright than black clubs. These clubs are more advantageous for players with short arms whose wrists are farther from the ground.
Clubs with a flatter angle than black use the color code starting with red at 0.75 degrees, followed by purple, orange, brown, and gold being 3.75 degrees flatter than black.