Unfortunately, people think having a leopard in the mix you will get spots. Not so. Leopards are 50/50 heterozygous for patterning, and likely in this case momma is too. That means there is a 1 in 4 chance you get a solid offspring. Only using a homozygous in the mix will make sure the appaloosa shines through -- so snowcaps and fewspots are the true spot-makers.
I know, because it happened to me once early on when I started breeding appaloosas. Back then I had about every color leopard you could have -- before I really started studying the appaloosa genetics. Here's what made me do more research:
Here's momma - RJ's Pocahantas
Then daddy - Timberview's I C Spots
And baby - Castle Rocks Hidden Spots Wait N C
Needless to say, I was SHOCKED to get a completely solid bay colt!
After that, fewspots were my go-to's and I had several, but of course, couldn't let Spotty -- my buckskin leopard stallion go. He always seemed to give spots to me, although sometimes not to others that had breedings to him. Hard to explain to some people.
We know her last boy (Sulphuras Legacy Edition) threw several fewspot foals (must have a leopard or fewspot parent to make fewspots) so crossing my fingers Storm Duster carries on the tradition!