No offense but to prove a new gene it takes more than just one breeding producing a similar patterned animal.
If you selectively breed certain reduced pattern normals chances are you will produce animals with a reduced pattern as well, that does not mean you have a new gene.
The color variation seen in those banana is a normal variation that can be observed from one banana to another including specimen from the same clutch.
You will need more breeding which will include breeding an offspring back to the dam before making any conclusion.
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