Elizabeth Peyton, the artist known for tiny, dazzling portraits of radiant youth, is now painting tiny, dazzling portraits of radiant middle age. The change is so subtle you can miss it, and it’s not even in all her new pictures, some of which just seem pretty -- although one should never bemoan such a delicate touch and honed sense of too-muchness. Yet Peyton’s lavender, lilac and crimson love letters to the age of innocence are finally reflecting the age of experience. Her deft brushwork and starry-eyed doting are still in evidence, but her color has darkened and her gaze is less moony. Several of her subjects look world-weary, like they’re living life, not just being fabulous. Some artists, like Robert Ryman or On Kawara, aren’t expected to change, because their work is about continuity. But change is built into what Peyton does. That’s why these signs of growth are good.