As good as Kim Kardashian looks in a bikini, she wanted some support under the red dress she wore at Thursday’s Heart Truth’s Red Dress Fashion Show at Bryant Park. So she borrowed a pair of Spanx from equally voluptuous Jordin Sparks of “American Idol” fame. Meanwhile, Sparks painted her mother’s toenails backstage. Raven Simone, after the runway, kicked off her heels and designer Pamela Rowland picked them up. Joan Collins, who was later spotted dining at Swifty’s,came into the park with her hair and makeup done. No one touches her face.