I've been propogating Xenia for over 20 years to lfs. Trying to find the most appealing color to sell. So for me it's all about the way they look when I first bring them in, and if they don't sell in the first few days the color fades, and they seem to become less appealing to customers. Because most stores these days, use higher kelvin lighting to make coral more appealing to look at. So yes they can, and certain ones like Elongata will change more than others. It is all about your lighting and water conditions, and from my experience intense light (400+ par) with kelvin temperatures around 10,000, particularly under MHs will give you the most color contrast. I've also been able to get some really nice colors under black boxes with the whites turned all the way up.