Halichoeres ornatissimus. It seems there are four similar species, two of which have been confused until recently. Halichoeres ornatissimus is restricted to the Hawaiian Islands and Johnston Atoll. Records of the species from elsewhere in the West Pacific are based on the recently described H. claudia. If you do an image search on H. ornatissimus you are likely to get both species. Aside from a few slight coloration differences (e.g., males of H. claudia have a large dark spot on the dorsal fin), H. ornatissimus attains a larger size.
Tony