I have heard some breeders say that chocolate & liver are 2 different shades of the same colour in the same way that red & gold are. I'm not convinced by this at all - nor is Peggy Grayson who has written the definitive book on Cocker history
Most breeders choose to register their pups as liver or chocolate depending on what name they actually prefer - the older breeders register as liver & the more modern ones as chocolate. Commercial breeders always use the term "chocolate" as it's more appealing to their buyers
So take your pick - as with lots of subjects, opinions differ
Going back to the list, you could add orange & white ticked & lemon & white ticked as well as chocolate/liver roan & chocolate/liver white & tan. Sable isn't included in the Cocker Breed Council list of accepted colours but it is well established in some European countries so it depends on your perspective