This common species appears to be quite variable in color, although it is not certain all the photos below actually represent the same species. In the first few photos, the orange color in the disk is visible at depth, so it is being emitted at the orange wavelength by something in the animal itself.
The two photos below are the same shot using still photo mode on a video camera, the first using artificial lights that wash out the orange being generated by the zoanthids, and the second with available light and a reddish filter for reducing the blues.
Some apparently different color forms.
Created 1 August 2018