Everything I’ve heard said that they can get darker as they age, but Moshi has gotten lighter. His face used to be mostly black but now just his nose is black and the fur around it has black mixed in. I think it just has to do with the individual bunny.

I think it is pretty normal for bunnies to change colors. That sounds like a nice change.
I don’t think my bunnies could change color much. They pretty much come in white, white, and white.

Horses can fade considerably. Like dapple gray horses always fade to white eventually. Often darker in summer though.

Lippizaner horses (the horses of the Spanish riding school in Vienna) are born black and then quickly fade to white. It’s to do with over-production of dark pigment that exhausts the pigment-cells in the hair. They still over-express melatonin in other parts of the body like the skin.

Not saying this is the case with Harley of course. It’s just a fun fact, sort of =)

Bramble has changed colour twice. When he first came home he was a light brown pretty much all over, over a few weeks he started getting more and more grey until he was almost completely grey. Then I swear overnight he was brown again, it really was like an overnight thing. Now he has a strange mix of brown and grey, with a black face. He is grey on the bum, brown on the back and black in the face, its strange but remarkably cute. Its apparently quite common for bunnies to change colour, although Brambles overnight colour change did have me worried for a while just because it really was a very quick change.