MAKING IT OFFICIAL: Long considered an unofficial kickoff to February’s New York Fashion Week festivities, amfAR’s black-tie New York Gala will this year make for the sanctioned start of the fall ready-to-wear season. The party, set for Feb. 6 at Cipriani Wall Street, will play host to Mercedes-Benz Fashion Week’s ribbon-cutting ceremony as well as the usual retinue of well-heeled fashion familiars in town for the shows. The HIV-AIDS charity will honor its chairman, Kenneth Cole, as well as Janet Jackson and Heidi Klum at the event. Cee Lo Green is scheduled to headline.