These are all red or burgundy. There are many others in blue and golden and bronze, but maybe you should tell us what size and form you like.

Perennials:

Panicum virgatum 'Shenandoah'
Panicum virgatum 'Rotstrahlbusch'
Panicum virgatum 'Squaw'

Annuals (in your zone)

Pennisetum 'Burgundy Giant'
Pennisetum setaceum 'Eaton Canyon'
Pennisetum setaceum 'Rubrum'
Pennisetum glaucum 'Purple Majesty'
Pennisetum glaucum 'Jester'

Thanks for your reply Donn!!
The ornamental millet Purple Majesty looks pretty good to me. I've often seen it sold in large pots for autumn displays. Do you usually grow it from seed or can you buy them in flats at the nursery cheaply? You don't think I'd have any trouble with this grass on a fairly steep slope?
I had actually looked into the panicums before I posted the first time (switch grass, right?) and I think I figured they would need more moisture than I could provide. Also, I seem to have the idea that they don't really get good colour until later in the summer. Is this correct?
I'm not fussy on form or even size really. My main objective is to provide contrasting form, texture and colour to a mixture of shrubs that will not be very exciting by themselves. So I know grasses will provide contrasting form and texture, it's just colour I need now--that's why ANY burgundy, blue, gold, silver will be okay--just not anything in the medium green range.
Thanks, Lizzy

Lizzy..'Purple Majesty' will do just fine on a slope, and you can grow it from seed. After growing it once, you'll have all the seed you need to keep growing it every year.

As to the rest, I'll make the same suggestion I made in another thread. Get a copy of The Color Encyclopedia of Ornamental Grasses by Rick Darke. ISBN 0881924644. It's full of photos of grasses in various seasons and positions. It also contains lots of cultivation info like hardiness zones. It'll not only teach you how to select grasses, but how to take care of them.