Custom Coins / Tokens allow players to design a horse how they would like (with limitiations).   Breed Coins, Magic Tokens, and Spectral Tokens can be used directly from the players storage or be used straight from the design lab as long as the player has one.   Chincoteague Coins must be used from a players inventory.

Breed Coins are available at all times  ||  Magic + Spectral Tokens are available throughout the year for special sales usually around holidays
Chincoteague Coins have only been available to buy twice:  When Chinco's were added to the game, when Chinco's receieved their V2 art.