Hi TKD, what color substrate do you have; is it light? Some time ago, I changed out my regular colored sand in the 20gal (I really like sand) with Tahitian Moon sand (black), and boy what a difference. First I moved out all those juvies, who seemed to be taking forever to color up, into two 10 gal which already has black sand or substrate. But in the process and with much thought as to how to deal with an exploding population, I finally decided to make the 20 gal an "All female RCS shrimp utopia!"
So far I have 15 females who have matured enough to have saddles (that's how I know when to move them in there). But just to let you know, even with black substrate, the shrimp still do vary in color intensity at different times. Then there are those times that they are day-glo red; it's surreal and sort of ridiculous-looking in that it looks fake.
The shrimp seem to have times they are more see-through (which makes their color less intense) and times when they are less see-through (which causes light to reflect off them and be more intensely red). Don't know if that makes any sense.
Do you have fish (neons?) in that tank? If so, that could be another reason for shrimp hiding more.
I've pondered the Tigers/BB thing too, as Tigers would be another shrimp I would want to try one of these days. Right now I'm leaning towards the idea that they very well could cross breed. I did read one thread where someone witnessed hybridized offspring of BB's and CRS, though of course I only have their words to go by. Since it's assumed that CRS, Bee and Tigers will hybridize, it seems logical to assume that if BB's and CRS do, it seems BB's and Tigers would too. *BUT that's purely speculation on my part and would love to hear anyone else's opinion. In the end though, if there's a "slight chance," I tend to be conservative and op to keep them separate.
Additional info: Hwchoy verifies Tigers and Bees hybridize (second to last reply on first page)
viewtopic.php?t=331&highlight=jaguars
But I haven't read personal reports about Tigers/Bumblebees yet.
-GB