Thanks for sharing your findings, Briggadane.
Blue Pearls are actually a different shrimp (Neo Palmata) than cherries (Neo Davidi). So you by breeding it back to a cherry, you probably have blue rilis. Or call it your own strain name since it wasn't thrown from a RR, and there's no way to tell if it is a blue rili unless breeding it to another blue rili to see if it throws wilds. (Even then the blue may be a simple recessive or dominant or co-dominant color, but I digress.)
Also, blue diamonds come from a selected strain of chocolates anyway. The actual blues that are thrown are a small % of those chocolates. So what you did was take a throw from a chocolate strain and breed it back to a chocolate strain.