Crickets diseases?

Hello
I have my own cricket breeding since a few months. Everything was going exactly the way I wanted...
But yesterday, while I was doing cleaning purpose, I found about 12 that were kind of grey/black ... They act very slowly compare to the others...
I have separate them just to be sure...
Someone have an idea of whats going on with them, could it be normal?? Im affraid that they are affect by some kind of disease...
Do you think its still "safe" to give the rest of the other crickets that look healty to my animals? I really doesnt want to take any risk...
I need your opinion
Thanks
Cya
Denethor

I was wondering what you figured out on the grays? I have seen that before at petshops that order mass quanities and dump them in the cage..If they seem questionable. Follow the old saying, "When in doubt, throm them out". Did you notice any mites?

yeah, well i'm not an expert ofcourse but it could be that they are ready for shed.....my crickets are also turning a little gray/dark just before shed, could it be that?

it depends on how gray/dark they are!
you got any picture?