Which 소 breeds come in 단색?

Club breed standards describe 단색 for the 브라운 스위스 및 저지.

소 pattern

단색

One color all over with no pattern or white: self in rabbits, cavies, rats and canaries; a tongue or hoof of one even color.

5 소 breeds list 단색. It is in a club standard for 2 breeds.

Breed	PDCA	BROWN SWISS USA
브라운 스위스	표준 (“solid brown”)	표준 (“solid Brown”)
저지	표준 (“with or without white markings”)	No ruling

How 단색 can appear or change over an animal's life.