Yes, they are really exotic -- they are Registered Quarter Horses. LOL.
But, I have also had many Arabians years ago and several of them were also gray.
I sold one of my AQHA stallions, Classical Silver, to a man that lives south of Mexico City. He is breeding him to a large herd of Andalusian mares to get more athleticism and quickness in the horses he breeds for the bull ring.
I just sold my last AQHA gray stallion to a lady in the UK. Several of his foals were already there and the people in Wales that had them loved them, so she bought my stud, War Chiefs Pride. He is a double bred Driftwood horse. About 10 of the grays I have now are his daughters. I still have 2 Classical Silver daughters