I would add that reds seem to breed much more true, thus keeping the "supply" side of this equation higher. I cull so many blue dreams every time I get into that tank, and rarely have to cull any from my bloody Mary tank. I also cull a few goldenback yellows, but not nearly as many as blues. My black rose project just turned into a cull tank because if I culled with any consistency there would have been almost none left.
I'll also add that yellows and oranges have produced larger numbers for me than even reds, though this may have been coincidental. I use the same water, food, husbandry, etc on each tank but some simply do better than others. Part of that may be fecundity of the shrimp lines, not necessarily related to color.
In my own tanks, if you wanted 20 bloody Mary shrimp from me -I could net out 20 perfectly red shrimp easily yet if you wanted true dark blues, I'd be netting around for a long while to find specimens that fit the bill.
I once bought a group of gorgeous blue dream imports. They were the only shrimp in their tank. I wound up putting the entire tank full into a cull tank. They never threw one remotely blue baby, 100% wild types. Here's a photo from that disaster showing a parent shrimp and a few offspring.