For a brilliant splash of purple, consider 'Sugar Plum' Coral Bells (Heuchera). I have it edging a long border with bluebells and a white evergreen candytuft plant ( don't know name). They soon reproduce themselves too, so are good value.
Incrediball Hydrangea arborescens Shrub - The size of basketballs, these flowerheads open a shade of key-lime, then mature to snowy white! Excellent planted near Paper Birch Trees which attract Downy Woodpeckers.
Front Yard Tree: Pee Gee Hydrangea Hydrangea paniculata 'Grandiflora' Flowering Shrub with Large White Flowers Adapts to a Wide Range of Climates from Zones 3 to 8 Only Hydrangea that can be Pruned into a Tree to High by to Wide
Brass Buttons ~ Leptinella Squalida This is a really fun miniature ground cover that resembles miniature ferns. This would make a great forest floor for a wooded fairy garden. Complete with tiny yellow button flowers when blooming.