However you choose to see it, Von Furstenberg has style, and his absolutist pronouncements about how men should dress--for business, leisure, and travel--could outfit entire boardrooms in impeccably conservative attire. For suits, only navy, gray, and tan will do; brown is, as Charles Revson noted, the color of you-know-what. For shirts--ironed, of course--the palest solids are best. ""Stay away from any dark solid shirt for business, unless you work for a godfather."" ""Relate"" sock color to tie color and accessorize smartly. Leisure clothes permit a bit more variety, but even jeans can be Egon-ized: ""Denim jeans with an ivory silk shirt and black velvet jacket make a modern statement that is very elegant, especially with a dark red silk tie and fine boots."" All this, plus the current wisdom on fitness and grooming. Grungies, pudgies, and limited budgets will have to look elsewhere; this is for the trim and well-heeled vanity case.