Hmmm . . . I didn't know there was a "true" yellow compared to a "non-red" Yellow. I thought all yellows were "non-red" Yellows.
According to Dr. Gene Lucas, yellow colored bettas do not result from the action of a single gene . There is no such thing as a yellow gene that produces a yellow phenotype in Bettas. Yellow Betta are phenotypes. The yellow color itself was designated as 'non-red' by Lucas.
As far as I know, if constantly bred towards yellow, they will eventually produce 100% yellow - but with different intensity. But since they will eventually become dull yellow, they are often crossed to different colors to enhance the yellow. Thus they seldom breed true . . . I mean not produce 100% yellow. Black, for example is one color they are often crossed to - thus creating pineapples and chocolate.
I just learned that Yellow females are used to produce various colors. I need to confirm this though . . .
Anyway, the premise believes;
1. Male passes on more color genes than female
2. Yellow is not a single gene, but a combination of various genes - thus very recessive
My question is (what I need to confirm) . . . doesn't the genes that make up yellow affect the color outcome?
A friend said;
Super black male x Golden yellow (not sure what he meant exactly) female = majority super black
Fancy koi male x Golden yellow = majority fancy koi.
Just thought you wanted to know . . .