A non red fish showed in a line. It is so called european blau or in russian nomenclature low ee (lowerer synthesis in erythophores). It is a recessive gene, which reduces red pigment on a body but can left some red in fins – it depends on exact color cells.
Photos of brothers. One blue, one normal.
With age more blue show on a fish.
Below examples of no yellow (MMGGeeXX) or so called Purple body fish in comparison with wild coloration brother.