>>57029763These are colored patterns or fur/skin/scales/feathers that emulate clothing, in the case of Gothitelle, Jynx, and Gardevoir they are folds of dead skin similar to Scrafty, Machamp are black spots on their skin, Sawk and Throh have white fur that looks like a Dougi. Some create accessories like Machap's champion belt or Sawk's black belt.
A real life example would be the penguins that from our perspective look like they have small tuxedos, some gibbons and bears have patterns similar to clothing, or the panda that seems to have pajamas.
Pic related is how a Lucario, Zeraora, Cinderace, Meowscarada would look in our world.