Ahh, ok. I didn't realize you let your kitties out. Thought they were indoor only.
Here's an article I found on daylilies and lilies. Two different species related but not directly so.
http://www.au.gardenweb.com/forums/l...101418189.html
And another one - same forum, different topic...
http://forums.gardenweb.com/forums/l...364525964.html
So there are Bellflowers (Campanula), Blanket Flower (Goblin in particular), Coreopsis, Black Eyed Susan (Rudbeckia), Astilbe, Coneflower, etc........ for long lastingness. There are many more but I don't want to overwhelm you too much.
Shrubs would be a good idea there but you want colour. Shrubs still require some maintenance to keep them looking nice and compact. You could put an aubrieta or a creeping phlox in the front to give you some early spring colour and the leaves will stay green all summer. You don't need a lot of plants as they will quickly grow in to fill empty spots. Then put no more than a dozen plants in behind. Spread out to give room to grow. I'm not talking a huge variety of plants. There isn't the space. Just one or two, possibly three, different ones for variety and colour.
http://www.gardening-tips-perennials...pingphlox.html
First I would recommend a treatment of cow manure and a good garden soil or a three way mix ot revive your ground in that area. Blanket Flower likes poor soil. The other ones can be a little pickier.
Whatever you decide have fun with it. Gardening really is fun.... you just have to get past the bone jarring weed pulling, plant moving, watering, etc. etc. etc............