I, too, have some tested homozygous silver mares that look palomino during the winter. They are both lighter overall - but they also live out 24/7 and I've found that the minute they are fully shed out they also fade. They are both heterozygous black.
And then there is this filly..... Both of her parents are tested homozygous black. Sire is homozygous tobiano & heterozygous silver, dam is heterozygous tobiano and silver. I'll show her older pics first...
And here is what she looked like when she was born...
I love the silver dapples! They are always different colors and constantly changing...
So here is a colt, too....
He's not chestnut.
Roflol!!!