[Aqua Pro Builder]

No idea what will color them up in general but at least I observed that with changing environment, their color will keep on changing. I have couple frags from JHale for which the polyps body is very brown and the tips are very green when I got them. I was told that they are purple digitdatz. After a couple weeks, brown turns light purple and green turns to lighter green. Couple months later, the polyps body turns clear and the tips are same color. There are a lot of skeleton growth but the poylps are not as dense as before. Most recently, the body of the polyps turn to brown again. So far, I have seen it in purple for a period of two three months which fit its name while all other times, its color-changes never match its name.

So I assume if we alter or deviate from the environment they live in, they will change color and may( or may not due to health issue) stay in that color we like. The color may not be the most natural or heathly though. So I have witnessed color changes but not color ups. Hope some can share thier experience.

From my own, I feel temperature changes cause color changes greatly.