Hey guys, just after a confirmation. I've done a little research and i think my Leo to be a high yellow - but the dude i bought him off said he was a mack snow?
There's no way to know whether or not it's a Mack snow by the time it gets to that age. Many Mack snows yellow up by adulthood. The only ways to know for sure is if someone reliable saw it as a hatchling and it was black and white, or if you breed it to a non snow and get snow babies.