Oh, I forgot to mention that I want to keep the height to about 6-8 feet. Thanks!

Ninebark has exfoliating bark, maroon leaves and flowers in the spring. There are several different varieties.

Whart about a Korean Spice Viburnum, Juddii, or other viburnum? Not all have fragrant flowers.

4 season of interest, no pink, fragrance, and flowering is an awful lot to expect of a single plant. If there is room for more than one plant, you can combine several to get this, but I doubt that any one shrub will do all of this. Perhaps you can plant some annuals or perennials around the feet of your shrub to provide interest when your shrub isn't providing interest or you could plant a light weight vine to climb into your shrub to provide summer flowers.
-Weigela won't be of interest in winter, but will be the other 3 seasons. Some have variegated leaves, and they have either red or pink flowers, so check on specific varieties for flower color
-Variegated colored twig dogwood. They are available with yellow or red twigs for winter interest and either gold and green or white and green variegated leaves for interest spring, summer, and fall. Not flowering in an ornamental sense, but the leaves are as ornamental as flowers IMO. Not fragrant.
PJM rhodies have lovely deep mahogany foliage in winter, though it does curl in really cold weather. It's a deep reddish green in warm weather. Flowers are a screaming magenta (does that count as pink for you?) though 'Landmark' has a deeper color. No fragrance, but 4 season interest.
Viburnum carlesii or Burkwoodii have lovely scented spring flowers and fall color, but are fairly boring in summer and winter.
Fothergilla has spring flowers with a light honey scent, basic green summer leaves, and gorgeous red, orange, and gold fall color that hangs on later than most other autumn foliage. No particular winter interest.
Birdsnest spruce. No flowers, but 4 season interest.

I know all of these will grow for me, but I am not sure if they will grow in a full zone 4, so check their hardiness. Regardless of what you plant, it will need care the first year and will need watering in long dry spells. Putting mulch under it will cut down on weeding.

Alternatively, grow a type 3 clematis on a pretty trellis. The trellis will provide winter interest, there will be a long sason of flowers, but they don't have a scent.

Burlington is practically infested with Carol Mackie daphne. Depending on just how cold you get, it may be a possibility.

What about Oakleaf Hydrangea? There is one called "Pee Wee" that is supposed to be in the 6-8 ft range.