I have a "new" color that has appeared spontaneously in pot with another color.
How Are Different Colors of Zygo Cacti Created?
Certified GKH Gardening Expert
This is called a sport. A sport is an offshoot of a plant that exhibits characteristics that do not conform to the parent plant. They are typically caused by a mutation. If you propagate the sport through cuttings, the cuttings will also have the same colors as the sport.