American pitbulls are bigger, 20 lbs heavier at least, and colored different than AmStaff, at least in my world. They are NOT the same animal. I have had one of each.
PS - nice freindly discussion, hope the OP doesn't mind.
Color is largely irrelevant according to the published breed standards of AmStaffs and APBT's. I think excessive or all white is a fault due to the link with deafness, but nearly any color is acceptable. Maybe not merle though. Can't remember exactly. Been a while since I've reviewed the standard.
What you are describing are not actually Pit Bulls, no matter what their breeders or owners want to call them. They are dogs that do not conform to the APBT standard, as determined and published by both the UKC and ADBA, and are not the offspring of registered sires and dams.
Actually, *real* APBT's are a small to mid-sized, very rangy breed. Most ADBA registered dogs are quite a bit smaller than typical AmStaffs. Backyard breeders are satisfying demand for a bigger, tougher looking dog, and in doing so have created a mixed breed animal with ancestry that includes everything from Dogo Argentino to Dogue de Bordeaux to who knows what else. Those big blocky dogs that look like they were weaned on dianabol are *not* APBT's.
Here's what I think you're describing:
This dog may be sold as a Pit Bull, but it is actually a mixed breed. Even if someone hangs papers on it, it doesn't conform to the breed standard.
This is an example of a real APBT:
This is a typical ADBA Pit Bull. His physical form follows function, as he was bred for supreme athletic performance, not to look tough and scary at the end of a logging chain on someone's porch.
Just for grins, here's my rescue:
I've competed with this dog in everything from dock diving to personal protection, and he's the best working dog I've ever encountered in over a decade of competition. Bomb-proof temperament and grit. He just refuses to quit once he's committed to a task.