When comparing the bottles, OPI Houston We Have a Purple and OPI Miami Beet looks very much alike (the picture below is taken in full sunlight and the colors look a little lighter than they are).
Looking at the bottles, DH said that he could never tell these two apart. Look again I said and showed him the nail wheel below (not that he was really interested or anything). The big difference between them is of course the formula. Houston is a jelly and Miami Beet is a creme.