When planting ornamental grass, consider color. The options are actually much more diverse than the typical green that comes to mind. Grass comes in many colors including cool colors (those that fall within the green/blue/indigo/violet end of the spectrum), warm colors (red/orange/yellow hues) and combinations of both cool and warm colors.
Grass color types include cool colors. 'Purple Majesty' millet (Pennisetum glaucum) is an annual ornamental grass that displays purple leaves, grows to a height of 4 feet, and thrives in U.S. Department of Agriculture Plant Hardiness Zone 4. Little bluestem (Schizachyrium scoparium) is a dry-climate, ornamental clumping grass with bright blue leaves that turn to purple during the fall season; thriving in partial shade and preferring clay soil, this drought-tolerant grass grows to a height of 2 to 3 feet and is hardy to zone 3, according to the Colorado State University Extension Service.
Grass in shades and tints associated with warm colors add a dramatic touch to the garden. Flame grass (Miscanthus 'Purpurascens') is an ornamental grass for moist garden areas that displays pink flowers; grass becomes orange-red during the fall season, resembling flames. Flame grass thrives in full sun (but tolerates partial shade), grows to a height of 5 feet, and is perennial to USDA Hardiness Zone 4. Red fountain grass (Pennisetum setaceum), is a warm-colored annual ornamental grass displays red blades; thriving in full sun, this grass prefers well-drained soil and grows to a height of 4 to 6 feet. Grow fountain grass up to zones 9 to 11, according to the University of Florida IFAS Extension.
Ruby grass 'Pink Crystals' (Melinus nerviglumis) is an annual ornamental grass that display pink blooms and blue-green foliage; thriving in full sun and reaching a height of 1 to 2 feet, this grass grows best in zone 6. Another combination option is ribbon grass 'Feeseys' (Phalaris arundinacea) that displays green stripes over pink/white-hued leaves; this ornamental grass thrives in warm, moist environments, reaches a height of 2 to 3 feet and is hardy to zone 4. Big bluestem (Andropogon gerardii) is an ornamental grass that thrives in dry conditions and displays erect, blue-green foliage that turns orange during the fall season; thriving in moist, sandy soil (with tolerance for dry soil), big bluestem grass needs full sunlight, grows to a height of 3 to 6 feet, and is perennial to zone 4, according to the Colorado State University Extension.