Are you seeing purple??? I think you should at least see some of the fan leaves with a hint of purp. . . Do me a favor and the next time you water drop like 4 ice cubes in each pot. Let me know if I am speaking out of place, but you got to get that room down to 50-60 before any major purple will be showing. . . Cold is key. . .Purps. tend to be a very damp plant so if it has the heat and the light it will grow like crazy. . .