Oh my goodness Po! That's cray-cray! O.o You're so lucky! Are you going to breed her a gajillion times so that her gorgeous coloring can be passed on? I sure hope so!
Speaking of which, Lacey also majikally turned into a paint! I'm not really sure what color her spots are though, maybe someone can help me figure that out? I'm pretty sure it's something rare, I've never seen anything like it before in my million bazillion years with horses!
[I saw the title of this and I was all about to be like "Po, you know that 'tri-color paint' is not actually the correct term, right?". Hahaha]
KV, Kiara has a black tail, which is completely normal on a brown horse and required for a bay. It's more than common for a horse with the tobiano gene to have a tail that is half white, but since Kiara's entire butt is white, it makes the black on her tail stand out more than it normally would. She's just a bay tovero.
I am also pretty sure you can't register a horse a tri-colored anyway. Most registries are pretty behind on color genetics and have rules about patterns. She would still be registered as brown tovero, I would imagine. Abby has two spots but they aren't big enough for her to have normal registration, so she's breeding stock. That doesn't mean she wouldn't actually be an overo. (I haven't actually tested her for OLWS, so I'm not 100% myself.)