No, I haven't culled them yet; they are still in the same tank as my Red Rilis. I don't think I would mix the two, if I purchased Blues separately. I'm keeping mine together thus far because they are from my original Red Rili group, so from the same line/batch, and I'm not too focused on selectively breeding Rilis yet; more on CRS/CBS.
So I shouldn't worry about them being in there together? I don't have any more room for another tank. They look like red rillis to me. Sometimes I have a hard time telling blue rillis from blue pearls to be honest.
Yeah, it's hard to tell on the ones with little or no red. But I wouldn't separate the red rilis and blue ones, that would be pretty labor intensive. Maybe separate the adult red rilis from the adult blue rilis, that should be easier than trying to sort through fry.
i just had one clutch hatch. they all look red/pink so far. i have another 3 females that are berried. hope they turn out well... i was expecting higher quality when i got the shrimp in. most look like blue pearls and only a few had rili markings. even then, only a minimal amount of red coloration is evident. i suppose i need to do some quality control and culling when the shrimplets grow.