I've been collecting heuchera ever since, hoping to imitate this. Ajugas also come in a multitude of colors, from silver to bronze to a fairly bright purple. Pulmoniarias offer white spots like spilled droplets of milk. For something with more height, there are some wonderful new Japanese maples to try. A source for these, and many other great foliage plants is Aesthetic Gardens .
Cannas have fabulous foliage.
Bengal Tiger, with its bold stripes of green and gold is a real show stopper, but I have a sneaky fondness for red flowered cannas with burgundy leaves mixed with the bold bluish burgundy foliage of the castor bean. I never knew red and purple could look so well together. On a quieter note, consider the old rose. I love it for its leaves, a steely grey blue warmed with a blush of burgundy. You can find it online at Garden Valley Nursery .