NEW YORK — Whether it’s the glitter of metallic lace or silk charmeuse, designers are bringing lots of shimmer to their collections this spring. At Reem Acra, the designer sees spring as the moment for “home entertainment and casual dressy evenings.” It’s translating into looks such as richly embroidered cashmere sweaters or a long dress that has a touch of tailoring with French cuffs. And color is important, here, in a palette of soft sorbet hues. Meanwhile, Bob Mackie evolves with simpler silhouettes without losing a bit of his drop-dead glamour — a sexy little black dress edged in satin or an embellished cardigan over silver jeweled lace pants and bustier. But of course, there are still plenty of those signature beaded gowns.