I couple days ago my plant started to turn yellow and purple. It is in day 41 of flower. The strain is Purple Paralysis, but I feel it must be too early to be turning purple. Phosphorus deficiency maybe?
If you have a control unit, just make sure its functioning correctly.That's the absolute lowest it's ever been. I have a thermostat built into my cabinet to keep the temps regulated. When I'm working on the plant and leave the door open it drops in temperature.