Arkansas Blue Star - Perennial of the year for 2011. It has blue flowers in the spring and fine, feathery green foliage in the summer. The show of colour it puts on in the fall rivals a Japanese Maple. Zones 5-9
Pennisetum Rubrum "Fireworks" Looks like something from a Dr Suess book! Pennisetum Rubrum is my favorite grass, I wish it was a perennial around here, I'll have to remember to get some for around he house this year.
Little Bluestem A lovely, tough-as-nails prairie native, little bluestem offers gray-green leaf blades that turn bold shades of purple, red, and orange in autumn. Name: Schizachyrium scoparium Growing Conditions: Full sun and well-drained soil Size: To 3 feet tall Zones: 4-9 Plant This Grass Because: It has beautiful blue coloring in summer and good fall color.
Tradescantia "Sweet Kate" - Sweet Kate is an easy-to-grow perennial that produces a profusion of unusual deep-blue flowers from summer to fall. An eye-catching accent for the border, the vibrant golden-yellow foliage is the perfect foil for its bloom and a bright companion for purple-foliaged plants. Height - 18 Inches Spread - 12-18 Inches Bloom Color - Blue/purple (Dry shade garden)
Lavender Hidcote - This easy-to-grow sun perennial thrives in full sun & normal garden soil. Plants vigorously grow to form mounds of fragrant, silvery foliage 18" tall & 24" wide. This drought-tolerant & hardy perennial has extremely fragrant foliage & flowers
The 7-inch spikes of veronica bloom atop 12- to 24-inch plants in shades of blue or red from early summer through fall: http://www.bhg.com/gardening/flowers/perennials/top-perennials-for-your-garden/?socsrc=bhgpin100914veronica&page=2