I usually read articles here and limit myself to posting tips but this is worth mention. If you see a great difference in color and feel your second source most here know to have better color genes, then you should really consider breaking the tank down to remove the weaker colored shrimp for various reasons. You could be setting your breeding program back considerably by allowing your two recent acquisitions to breed with possibly producing more weaker colored specimens. Second, Neos and Cardina are selectively bred to produced improved color strains and with the possibility of the results of your stock being dessimated to other hobbyist....it could set improvements years back again. Just a idea some would agree with.