Many visual morphs can be described as the inhibition of certain workings and traits in the cells. Whether it is the over production of pigment, the inhibition of certain pigments, or the placement of pigments during embryo development, they are most often "stopping" the cells from working and doing their jobs properly, resulting in our morphs.
These are very often passed down through simple recessives or co-dominant inheritance. Making it a genetic mutation (disorder).
If it is an attribute that is detrimental to the survival of the animal and bodily function, and is inherited through simple Mendelian understanding, I would call it a genetic disease.
They are all "disorders", but the severity to how they inhibit the natural and perfect workings in the animal warrants a different label I think. I could be wrong about the labels, but that's how I see it.