The Pyrocat mixed first as green, and it would turn color after a little while to almost black. I bought a new kit and it mixed green again. But it didn't help my developing problems any. I tried distilled water, which also didn't help. I can't even remember all that I tried anymore. Sorry I'm not of more help.
It could be that one of your solutions are contaminated, or it could be that you're not using enough agitation. I never solved this problem.