Rob...hardy and colorful, and basically full sun? Hm. My first suggestion would be miniature crape myrtles, but as a foundation plant, they would not be a great winter plant. Does that matter? Do you want/need winter interest?

I'm so, so not an expert on shrubs, but my favorite, old-timey Oklahoma shrubs/bushes are white spirea, lilacs, & forsythia. I imagine there are varieties of each that are either compact or large, depending on your space. I'm trying out rue (which can be irritating to the skin so keep that in mind for yourself/kiddos) to hide my gas meter that's in my front lawn. It's a different shade of green than most shrub leaves and it goes well with my house. Good luck!

Rue is an evergreen-type bush/herb - part of it's appeal as well.

Kate...it is a butterfly host plant as well for black swallowtails.

Edward Goucher abelia, the dwarf variety, will flower all summer. It can get to 5' tall, so not sure if you want something that large. It can be sheared, but that will limit it's flowers. Butterflies love it. Very hardy, and evergreen.

I have three regular sized ones, and love them.

Images from google:

Thanks everyone! Here's a pic of where I'd like it. I just removed the branches from this dying tree.... Debating taking the rest out or using it for something to climb on.

Ohhh, that makes a difference. You don't have much room at all for a shrub. Have you thought about a landscape sculpture type thing there? (your tree gave me the idea :) ) In the meantime, I would plant some vines on the tree!

Something that close to the door, I think you are going to want year 'round beauty, plus hide the hose.

But if you want a plant/shrub, you might look at a Jane Magnolia. They bloom this time of year. Jane Magnolia

Or maybe a rose of sharon? They will be taller.

Thanks! On another thread (where I was asking about the poor tree) it was suggested to plant a clematis at the base of the tree. Thoughts? Will that grow ok in OK?

Sure, clematis will grow here. Make sure you know which type you have. There are three different types and it makes a difference on the pruning. That being said, I have them, and I don't remember which type I have :) and I even knew better! An annual vine would give you quicker color though...let you "try it out", if you like. Red cypress, morning glory, purple hyacinth bean, moonflower.