I have 3 het clowns myself, 1.1 normal 100% het clowns and 0.1 enchi 66% het clown.

Markers for het clowns include lighter color and long dorsal stripe partially broken. But this is not for sure. Both my normals have the long dorsal stripe and the female is very light in color. The enchi has no markers but that does not mean anything at all. The breeder I got my het clowns from is super reputable and every breeder I know personally has a small collection that came from him. This is what I go on, not markers. I have many ball pythons who have clown markers but are not het for clown at all. Markers mean nothing.