white suppression - that is much less about an individual horse, and is much more about the color.
Extension as E tends to suppress white, so black suppresses it more than brown which is more than bay, and chestnut is the most expressive, all else equal (because Extension is e).
That said, some horses do suppress white, regularly producing chestnuts that should theoretically loud(er), but were minimal to solid.
And likewise, there are some bay/brow/black horses who have and produce lots of white - Popeye K for example.
So your best options are the black-based stallions with chrome who are known to produce it - PK, Amazing, Bliss MF (thought there’s controversy there too, so do the research and decide), the general Balta’Czar/Alla’Czar line.
For sure the Parcival babies who are red-based almost all have lots of white. I’ve seen quite a few black-based ones as well, but most of them also have dams who are (obviously) black-based and also with lots of white. Meaning, I don’t know how much white the black-based foals tend to get when from black-based dams with little to no white.
:lol: