Brunner credit per George Olshevsky's Marvel Comics Index Vol 1, No.7B.
Reply in letters page from Roy Thomas explains that Marie Severin does the coloring chores on most issues of Sub-Mariner she pencils (although she probably did not color the panels on this letters page, because Dorma is pink and the Lemurians are green [they were colored green in later appearances, but in Sub-Mariner #9-12 they were blue)]. Letters from Raymond H. Allard, Colleen Horton, J. Blocker, Don Tyler, Glen Quasny.