This is generally considered a color form of Phyllidia ocellata (see Gosliner et al (2018)). It does have some differences in color with the wide white ring around the black center and in sculpture in lack of light colored bumps within the black spots and in the form of two ridges, one on either side of the midline. Also it is quite curious that if this is a rare color form, how likely is it that two of the same rare color form chose each other to pair up with when the other color forms shown above are so much more common and so much more likely to be found if pairing up was by chance. I think this one could use more study. This photo was taken in the Padangbai area.
Created 15 December 2022