
landscapeliving answers:
Here are just a few suggestions:
Coleus-has lots of different foliage colors
http://images.search.yahoo.com/search/im...
Fuchsia-lots of choices
http://images.search.yahoo.com/search/im...
Ferns
Vinca minor (periwinkle)-a few options
http://images.search.yahoo.com/search/im...
Lysimachia nummularia 'Aurea' (creeping Jenny, moneywort)-to trail with gold leaves
http://images.search.yahoo.com/search/im...
Bacopa/Sutera-ground cover, available with white, pink, lavender or blue flowers
http://images.search.yahoo.com/search/im...
Lobelia-provides an abundance of flowers, annual and perennial varieties; ground cover or upright plants
http://images.search.yahoo.com/search/im...
Impatiens-lots to choose from
http://images.search.yahoo.com/search/im...
Dicentra (bleeding heart)
http://images.search.yahoo.com/search/images;_ylt=A0S0201EIkRI3ZYAOPGJzbkF?p=dicentra&fr=yfp-t-501&ei=utf-8&js=1&x=wrt
Polemonium (Jacob's ladder)-get the variegated kinds, so pretty!
Http://images.search.yahoo.com/search/images;_ylt=A0S0207LIkRIkOoA5ZiJzbkF?p=polemonium&fr=yfp-t-501&ei=utf-8&js=1&x=wrt
http://images.search.yahoo.com/search/images;_ylt=A0S020rYIkRIzhcAh1qJzbkF?p=polemonium+brise&fr=yfp-t-501&ei=utf-8&js=1&x=wrt
Corydalis-so pretty ususally you find the blue and yellow kinds
http://images.search.yahoo.com/search/images;_ylt=A0S020nzIkRItWQBYhmJzbkF?p=corydalis&fr=yfp-t-501&ei=utf-8&js=1&x=wrt
Heuchera (coral bells)-lots of foliage colors to choose from
http://images.search.yahoo.com/search/im...
Tiarella (foam flower)-a few choices
http://images.search.yahoo.com/search/images?p=tiarella&fr=yfp-t-501&toggle=1&cop=mss&ei=UTF-8
Heucherella (foamy bells)-a cross of Heuchera and Tiarella
http://images.search.yahoo.com/search/images;_ylt=A0S020mdIERI92IBGBOJzbkF?p=heucherella&fr=yfp-t-501&ei=utf-8&js=1&x=wrt
Lamium maculatum (dead nettle)-to allow to trail
http://images.search.yahoo.com/search/im...
Torenia (wishbone flower)-pretty
http://images.search.yahoo.com/search/im...
Begonia-lots of choices
http://images.search.yahoo.com/search/im...
Hedera (ivy)-good for filler, be sure to get non-invasive kind!
Campanula (bell flower)-lots to choose from
http://www.wildgingerfarm.com/Campanula....
Some Ornamental grasses will do well
Erodium (heron's bill)
http://images.search.yahoo.com/search/im...
Geranium (crane's bill) - true geraniums
http://www.daytonnursery.com/Encyclopedi...
Pelargonium peltatum (ivy geranium)
http://images.search.yahoo.com/search/im...
Pelargonium x hortorum - fancy leaf types
http://images.search.yahoo.com/search/im...
Viola and pansy
Pulmonaria (lungwort)
http://images.search.yahoo.com/search/im...
Digitalis (foxglove)
http://images.search.yahoo.com/search/im...
Helleborus (lenten rose)
http://images.search.yahoo.com/search/im...
Trollius (globeflower)
http://images.search.yahoo.com/search/im...
Abutilon (flowering maple)-lots of options
http://images.search.yahoo.com/search/images;_ylt=A0S020q.IERIJBkAQguJzbkF?p=abutilon&fr=yfp-t-501&ei=utf-8&js=1&x=wrt
Hydrangea-lots!
Http://images.search.yahoo.com/search/images;_ylt=A0S020sVIURIWCkBZXyJzbkF?p=hydrangea&fr=yfp-t-501&ei=utf-8&js=1&x=wrt
Ceratostigma (leadwort)-great blue flowers!
Http://images.search.yahoo.com/search/images?p=ceratostigma&fr=yfp-t-501&toggle=1&cop=mss&ei=UTF-8
Sambucus-nice lacy foliage, look for purple leaf varieties or gold ones!
Http://images.search.yahoo.com/search/images;_ylt=A0S020qoIURIoBcAdaKJzbkF?p=sambucus&fr=yfp-t-501&ei=utf-8&js=1&x=wrt
Viburnum (snowball bush)-can't beat them in full bloom
http://images.search.yahoo.com/search/images;_ylt=A0S0204AIkRIzuYA_aqJzbkF?p=viburnum&fr=yfp-t-501&ei=utf-8&js=1&x=wrt
Thalictrum (meadow rue)-nice dainty flowers
http://images.search.yahoo.com/search/images;_ylt=A0S02079IkRItOgA2zqJzbkF?p=thalictrum&fr=yfp-t-501&ei=utf-8&js=1&x=wrt
Acer (Japanese maples)-many to choose from!
You will want to double check with a good local nursery to see if these are good in your area. You can also add a few mixed containers on different height levels to add instant color and pop. I change mine up about every 3 months so that they are fresh and providing the bulk of "color" in the shady areas. These can be assorted shade annuals if you want. You can also add some specimen plants in pots and if they are elevated will create a nice focal point.
Good luck!