I would suggest using native plants. Good shrubs are native azaleas (which are deciduous but very fragrant when blooming), Calycanthus "Athens" or "Michael Lindsey", oakleaf hydrangea (many cultivars available), Hydrangea arborescens "Annabelle", illicium floradanum (Florida Anise with red blossoms).

Are you interested in more perennials? Unless you have a lot of ferns, there are still lots of choices to explore. What kind do you have now? Variegated gingers (like "Callaway) offer attractive year round foliage also. Variegated solomon seal is also quite showy in a group.

Colorful summer perennials are difficult to find for shade. By having a variety of foamflowers, I have blooms through June. Indian Pink blooms in May. Otherwise, I can't think of colorful shade natives.

Since impatiens self-seed well in our climate and love moist soil, I planted several impatients in the woodland garden last year, which I hope seed about to fill in after the spring ephemerals die back. The seedlings fill in my flowerbeds each summer though I haven't planted plants in years.

With damp soil, be sure to add virginia blue bells for spring color.

Lobelia cardinalis is a great bright red for damp,partial shade... Maybe some siberian iris too.

Thank y'all ....some great ideas..I did have an oakleaf hydrangea but the soil was too wet for it..I planted snowball viburnum and it has done well. I love the idea of lobelia and siberian iris as well as the different varieties of foamflower. Will native azealas do ok in damp soil? I know the cultivated ones hate it (learned that lesson the hard way). I love the natives and would love to plant some in there as a backdrop to the smaller perennials.

To overcome the dampness, I would build up an area (either a raised bed outlined by old logs or boulders for a natural effect or a soil berm) for the native azaleas. They do like good drainage, but you can create that yourself.

Virginia sweetspire is one native that can handle damp conditions. Arrowwood viburnum (v. dentatum) can also.

Here is a link that might be useful: Natives for wet areas

I think R. viscosum (swamp azalea) and it's hybrids don't mind the wetness as much as some of the others but still a good idea to amend (sand) and mound or raise the planting sites for native azaleas in a wet area. Lemondrop is a nice late blooming yellow viscosum hybrid. Serrulatum (hammock sweet azalea) actually likes it a bit wet, while it's not very showy it can bloom into September.

There is such a thing as the ever elusive "moist but well drained" soil which would give you lots of additional options. I'm thinking "heavily mulched" would mean lots of organics but that doesn't neccesarily preclude being well drained. If you dig a hole does it hold water?

Clethra, Hamamelis virginiana, Lindera benzoin all like damp shade. Shadbush is more woodland edge but likes wet as well.