These pictures illustrate what I am talking about when I use the term "cone shaped". The skeleton resembles a slightly flattened cone, or a V. The first photo illustrates the results of a coral with a very slow growth rate. The second photo illustrates a fast growth rate.
As far as color goes, I didn't even mention the corals secondary or photosynthetic pigments. What I did say, was that if the coral had not bleached, it would have very dark zooxanthellae. This is a result of the light the coral received in the ocean. At greater depths there is less light, so the coral houses a larger population of zooxanthellae to supply the nourishment needed. This gives the coral a much darker appearance. This is what we see in the Indo Pacific Elegance corals due to the fact that they are collected at much greater depths. In comparison, the Aussie Elegance corals have a lighter brown color. This indicates that they were collected in much shallower water where a smaller population of zooxanthellae is sufficient to supply nourishment and not poison the coral with an over abundance of oxygen.