Aside from the attractive foliage, both in terms of color gradations and patterns, another interesting aspect of Heucheras is the actual overall appearance of the plant in different seasons. Just as the chameleon will change color based on background, so to the Heuchera will change (often much more than just color) based on the season.
Sometimes this can make it difficult to identify a specific plant. Just look at all of the wonderful photos posted on this page by ATP members. And they are all of the same plant growing under different conditions and photographed in different seasons.