the genotype of the offspring would be RB, BR, RB, BR (well the genetic pattern of the fish varies for example the fish could have Bg meaning dominant blue and maybe recessive green im making this up and going into detail too much). the phenotype would have to be some sort of mix.
Explanation:
the genotype is the genes on the inside. i just use a table to mix it and assumed both fish were just pure blue/pure red. the phenotype is what's visible. it would be a mix such as maybe purple or red here and blue there. this is since they are both dominant and have to be expressed. same for blood types (AB blood). sorry for late answer.
