The ad says he is FHANA registered. Maybe they are just keeping up with the times and allowing all genetic possibilities? I don't mind. If he isn't registered I will take him off their hands and start a new registry - SHRFAA - Super Hot Red Friesian Association of Australia.
I would say, just at a guess, that about 99% of Friesians today are EE, so homozygous for black. Then the other 1% are Ee, and carry red. In fact, the numbers are probably even higher in favour of EE to be honest. This boy was just a lucky dip. I would start testing all his full and half siblings though, and their get too. Chestnut Friesians could be the new "in thing" lol.
My instructor recently traded for a red FresianxAzteca mare. BRIGHT red, very pretty. If I remember correctly, it can occur naturally within the blood line, but comes out very commonly in crosses since Fresians are not all homozygous black.