Not scientific, but so far, only a few have been bred for cold climates. In addition to Imperata 'Red Baron,' there are Panicum virgatum 'Shenandoah,' 'Rostrahlbusch' and 'Squaw.' Miscanthus sinensis 'Purpurescens' is red-orange to red-brown in the fall, and hardy to at least zone 7.

I can't name any, but there are probably reddish Carex varieties which are hardy to colder zones.

I have no doubt that people are working on hardy red and purple Pennisetums, as we speak.

I grow 'Shenandoah' here along the Connecticut coastline. It's a magnificent grass that does well even during our coldest winters. However, for most of the season it's green with faint red/burgundy ends... not at all as bright as 'Red Baron' but taller, fuller.

Molie

there was a recent issue of Horticulture magazine that had a nice spread on a garden developed for drought tolerance. there was a beautiful photo of a curving path edged by different ornamental grasses (and others...i dont have the magazine, but i recall some euphorbia, etc), with jeweled color variegation. i wish they'd listed all the plants that were pictured. the combination of reds/bronzes/greens was really lovely. bronze carexes (for me) usually look brown/tan rather than rich reddish. i'd love a reddish or purple carex! but i typically don't see even the supposed purplish inflorescence of eragrostis as anything but tan.