I have noticed that some of my red cherry shrimp (even one of the chocolates) go blue over night or get sections of blue. This blue quickly disapears when the tank lights come back on in the morning. I dont use fertisers or even shrimp soils in my tanks so I am wondering is the colour change still pH related, or is it just at night time in the total darkness they feel they dont need to "hold" their normal colouration? I am also guessing too that this mean that all the ones that display this blue colour change, are they carriers of blue gene?