Yeah it would be nice to have some solid evidence as to what causes this. It seems that for every solution that had beneficial results from one reefer experience, there is another who experienced negative results doing the same solution. (Lighting intensity, feeding regiments, flow, etc)
I too have had an orange one lose its color, it was a beautiful specimen that decided to move under a rock one day and didn't peak back out until it had lost a good amount of color and tentacles became shrunken. I am going to try one thing at a time and give it a few weeks before I try something else, in better luck of hopefully pinpointing the reason. I am going to start with lighting as I am thinking it went under the rock to avoid the intensity of light it was getting.
