I know you use cooler temp but is that for the whole grow or just the last few weeks an how much lower should the temp be
If you really want them to colour it is a cross between the genetics and temps it’s mostly genes though.
What works best for me is a large temp swing whole flower period over 10 degrees difference between night and day. Dropping to 66f at night and hitting highs in the low 80’s though this takes good environmental control since humidity is harder to control at the higher temps
It’s funny because that’s how my temps are in my flower tent, and I didn’t even try to get it that way haha, luckily my basement is pretty much the ideal grow area
Mine stays between there to thanks Donaldj