Quite a few:
Blues - Spiderwort, American Bellflower, wild Blue Phlox, Downy Skullcap, Great Blue Lobelia, Camassias
Purples - New England Asters, Violets, Purple Coneflower (2 wilds), Dame's Rocket (pinkish purple), Turtlehead (pinkish)
Greens - Solomon's Seal, Snow on the Mountain, Ferns, Jack-in-the Pulpit, Rattlesnake Master
Yellows - Goldenrod, Maximilian's Sunflower, Black Eyed Susan
Reds - Ipomopsis, Leopard Lily, Blackberry Lily (orange), Campsis (orange)
Whites - wild Allium, Claytonia, Heath Aster
Trees - Paw Paw (brown flowers)
Time permitting, I'll dig up some photos.