Sometimes the appaloosas will roan out from pretty much solid to white spots all over to eventually pretty much white. Goer is an example of that. Our gelding, Prez and his daughter Fanny both are Goer horses and they did that.
That's Prez, when he was young his coloring was much like Lacey's.
That's Fanny and she did the same, solid except a couple of spots on her rump at birth. It took both of them about three years to do this, and each year they get a few more of the snowflake spots.
Some Appaloosas roan out with white hair replacing the base color until the only color left other than their spots, are "varnish" markings on their legs and heads. Indy and his mother, Farah did that. Don't know if Tuffy will or not.
This is Indy, when he was young he looked much like Tuffy, although his blanket had solid edges and wasn't as large. He also had spots in his blanket which Tuffy does not.
Then, some apps are born solid and roan out with white hair mixed with the colored hair, white spots, and colored spots developing as they roan. Dusty, Speed's mom was born solid with two or three white spots and a dun spot on her rump. She is roaning out to an almost leopard type pattern, a little more each year. She didn't start roaning until she was almost three.
Dusty two years ago and then two months ago.