Cold is one of the best things for cannabis in a controlled room, I guess it boils down to if you have the knowledge on how to use it or not. I've been using cold in my growing for 20 years or better, But I'm sure the guys that barely got their feet wet yet with growing will be here to tell me I'm wrong lol. Early in growth temps can be used to control stretch or add it, by maintaining consistent day night temp or making the nights colder or by just doing a cold dump for a couple hours in the morning, it also causes the plant to release or suppresses the release of gibberellin . later in flower you can use cold without questions to produce much higher levels of resin or resin concentration. cold in later flower will also cause the buds retain a much higher terpene content which gives you a much more flavorful and aromatic bud period. Cold can do far more then change the color of leaves lol