Hi Donny, I don't agree on the presumption that CB x CR will give 'brownie' offspring. If you keep CR/CB hybrids, you will get dark CB if no Snow White was crossed in either in the Red or the Black line. I have seen pictures on many Japanes blog where the kept them together, and no color loss was to be seen.
Hi Aokigahara, thanks for sharing your perspective. True, I have seen several tanks where CR and CB were kept together with no color loss in the following generations. I think the brown may have resulted with the introduction of Snow White/Golden genes in the parents, thus the offspring may have washed out colors. Perhaps if you have pure lines, you will not see the brown phenotype.
Aokigahara = Imke right? Lol, you threw me off with the different name :DI do have some CB with lighter blacks and suspect it is from Snow White/Golden genes. CBs are surprisingly hard to get here in the US, especially ones with solid coloration. There are some breeders that have been producing nice solid color CRs, and I noticed that they do keep some CB in the same tank.