Kev,
I put my Echinoporas under VHO in December. Before that, I had them in the shade under my MH's. The purple's whole body had those larger corallites/eyes. Once it was under a brighter area in the VHO tank, it started to get a little blue, and I noticed it was loosing the big round eye look. What you see now are the shaded areas that did not convert. The corals was on a slight angle in the aquarium, so there area a few spots with more purple color, and those wide open corallites. The rest of the coral has morphed, for the better, IMO.
Very strange. I can understand color changing, but skeletal changes just from different lighting is beyond me.
For these pics, I had to pull the corals out of my 55 gallon VHO tank. I put them on top of my Acropora efflo/soli so I could get a better shot. They did not show up good under the blue VHO's.