Proven by who?Coopers Constrictors
Pieds and Clowns are recessive... Period. I don't know why people are misinterpreting and over thinking proven information that has been around for decades now.
How dare anyone challenge the status quote
It's not the ability to have them, they all show them no different than a yellowbelly, or spark, or paint shows their markers reliably.Just because they may have the ability to have 'markers' and 'clean things up a bit' DOES NOT make them "codom" (btw... the proper term is Incomplete-Dominant, not codom)
I can't attest to pieds but het clowns are all visual, If you produce enough of them it becomes quite obvious.