Indoor Plants turned completely purple

[GockBuds]

I know cold temps will cause some plants to turn a little purple, but damn, my blueberry headband and cherry pie x wedding cake have almost turned completely purple after 3rd week of flower. My room was getting pretty cold at night until I got a heater in there. Possibly down to the 50s. Ironically my grand daddy purp stayed completely green Anything else that can cause this?

 

[gorillaglueaaron]

Genetics and cold night temps.

 

[GockBuds]

Tripped me out, 2 different strains look just as purple. I'm going to start doing this every round to get the color lol. Didn't seem to hurt or stress them at all. They should be getting all their phosphorus now that the Temps are back up and consistent