Fill the center of a large container with one or three dark-colored plants of either the ornamental cabbage type or the frilly ornamental kale variety, depending on the container size. Surround the dark variety with enough cream-colored or variegated plants to fill the container. Make a companion container by planting light-colored or variegated types in the center, surrounded by dark colors. Use either cabbage or frilly types for the center and other types for the outer plants.
Combine dark-colored kale with light, contrasting-colored plants such as chartreuse "Lime Rickey" heuchera or coral bells, pineapple sage or colorful coleus, also available in several leaf forms and many colors and combinations.
Plant a tall spiky plant such as dark purple phormium or purple fountain grass in the center of the container to add a bold statement. Surround the tall plant with either light or dark cabbage or kale varieties. A solid dark-colored container will add drama while a light-colored container will accentuate the contrast.
Pair edible plants with dark flowering kale. Tuck easy-to-grow herbs and greens such as basil, lettuce, arugula or oregano into a container with kale.
Plant dark-colored kale in a wide, shallow container, leaving spaces around the plants for a decorative mulch. Some creative choices are seashells, river stones, cocobean hulls, nut shells, colored leaves, small gourds, colored aquarium gravel and glass marbles or half-circles.