I had a bay roan who, in the summer was very pink. His colour was lovely and even and he had lovely bay head and black points with a black mane and tail. I saw a friend's new horse the other day and she was what she called a chocolate roan with was a very rich colour and stunning. You horse OP looks like somewhere in between the two in that picture. He's also a very handsome chap
Somewhere away back in the distant past around my pony club era, I can remember something about "mealy muzzle's" as seen on Dartmoor ponies and this is the type of colouring that they were talking about.
"Mealy muzzle" is a feature of Exmoor ponies...according to my old pony books. I must get a good pic of my boy in his summer coat as I have strong suspicions he's not a bay (on passport) at all....
Pangare, which causes mealy muzzles on exmoors and haflingers (which show the chestnut based version) is similar to the pale muzzle caused by Brown, but a pangare muzzle is lighter in colour.
Roan doesn't have to be on a certain base colour to work, however it would be hard to see on a pale coat (eg cremello). Roan adds white hairs to the coat in a certain way (the head, lower legs, mane and tail are left 'solid'). This is why true Roan horses are sometimes called 'dark headed roans'. Other genes also add white hairs/white flecks eg sabino and rabicano.
Strawberry Roan just means Chestnut Roan, so a chestnut base.
A Blue Roan is the same as a Black Roan. Bay Roan is just called Bay Roan. Brown Roan is Brown Roan, but Brown is one of the most commonly misidentified colours, so Brown Roans are sometimes wrongly called Bay Roan.
Colours that are often confused with each other.
Roan, Sabino and Rabicano.
Roan and Grey.
Brown and Bay.
Seal Brown and Black.
Palomino and flaxen chestnut (especially if the horse has pangare too).