SPS corals come in all kinds of colors but can change dramatically depending on the environment. For example, A green Acropora coral at the dealer may well turn out brown after it has been acclimated to your aquarium. And vice versa, a brown coral may turn out green after bringing it home.The color of a photosynthetic coral is dominated by the amount of zooxanthellae in the tissue. The higher the number of zooxanthellae in the tissue, the more brown the coral is. The extreme of this is when a coral bleaches, it goes white as all of the zooxanthellae has been expelled from the tissue. Color will vary depending on the lighting conditions in your aquarium. Actinic lighting or metal halide lighting heavy in the blue spectrum will enhance your corals' color. However, the color and health of your corals is also dependant on maintaining near perfect water quality in an established reef aquarium, with high pH, calcium and alkalinity levels, and maintain extremely low phosphate and nitrate levels as well.
