DESIGN dropped a pebble in water.” Combining the gold with silver “to make it look more modern,” Hirst created line extensions once Coty approved the lipstick look — compacts, nail polish, a foundation. (Don’t go looking for it. Although the brand was successfully re- launched in Europe and Saudi Arabia, it is not yet available in the U.S.) Hirst, 49, is at the top of his form, a leader in the ranks of cosmetic package designers. Debonair with a cheery Australian accent, he could 74