You're basically saying the same thing as me I believe. You're just more optimistic and in-depth about it. I'm a "see it to believe it" person.
So you're saying that OLWS foals are albino? When you say "overo spotting gene" you mean frame I assume?
Cool, lesson time!! Geek out with me!They are white by definition though. Zero pigment every time. I think that's where we are confusing each other. What I call white you call albino. Which works. I guess I've never called it albino in horses because there haven't been any documentation of it like there have been in other animals. If there had been, I'd likely call it albino too... if I knew that's what they were genetically. I'm a stubborn mule.
If you define an white as zero pigmentation, then dominant whites are also white, as are the palest cremellos. Because OLWS foals are not genetically white, only visually white. I am absolutely not saying OLWS foals are albino, nothing is further from the truth.
OLWS stands for Overo Lethal White Syndrome. Every overo/frame horse you have ever seen carries one copy of the overo gene (and possibly also a tobiano gene, but that doesn't matter here). Like Gray, like Cream, one copy of the gene gives a visual effect and roughly 50% of offspring with a Gray/Creme/Overo parent will display that effect.
You never, ever breed Overo to Overo (although I remember when folks did, took the 25% death rate as a given and hoped for a homozygous colt that could live, because frames were that $popular$, showing my age here) because all homozygous overos have a degree of OLWS, which, as the name states, is roughly 98% lethal, the lucky ones are midterm miscarriages before they can feel pain. But, like every other Paint/pinto, genetically, that is still a colored horse, with a gene that causes white to "paint" over part of a colored horse. A bay paint will will still throw another bay unless it carries a recessive for chestnut, etc.
An albino has no genes for color. This is a relatively common mutation that is always recessive. Depending on the species and how color is carried, sometimes Albinism is linked with other traits - in ball pythons, there is a type of albinism that is linked with spinal deformities. An albino genetically carries no color, the color of any offspring is totally determined by the other parent and you will only get another albino if the other parent carries the albino gene. Genetically (although, depending on species, not always visually) this is a white animal.
So, when we say "there are no white horses" it is a horseman's joke, because there are lots of ways to get visually white horses. What we don't have is a breeding population of genetically white horses, which does not mean that the Albino mutation has never occurred in the species (which would be very unlikely) and is more likely to be for the reasons I listed above.