No, true albinos do not exist in horses. It has been proven over and over again scientifically. If the horse you saw and you remember looking like that, I would guess that there was something medically wrong with it's eyes and not an albino
A true albino wouldn't have any blue in it's eyes anyways, the eyes would have been red, not pink.
The "albino registry" was started (in 1917) before there was the genetic knowledge of horses colors that there is today. The name has since been changed (in 1980) since they now know there are no albino horses.