I’m not sure if I missed it somewhere, but if you aren’t using a space heater, maybe give that a try. With me running my space heater I’d say the RH drops a good 10% all on it’s own, if not more. I’m forced to use a humidifier because of my space heater
No need to drop temps, trying to force color through temperature manipulation is gonna cost more in yield and potency than just maintaining optimal. Want color get colorful genetics. Plenty of strains known for purples, blacks, blues, reds etc just gotta run a bunch of seeds to find the prettiest ones.