Temp "fluctuation" is what brings on the most extreme color changes and terp and other oil production. Ask Mr. Jodrey about the subject.
If your plants roots stay around 50 degrees, it goes pretty much dormant and stops growing. lol
10 to 20 degrees temp swings of the plant material above ground is the best method. But don't take my word for it, I'm just a 40+ years of growing weed newbie. lol
K.I.S.S.
The theory of flushing, you are trying to remove Chlorophyll out of the cells which should just lighten your product. Years ago, you couldn't get a plant to turn colors unless it was built into the genetics.