Kalanchoe

Color (also known as hue) is a wavelength of light. Considering a piece of art, the observer may note the range of colors used or avoided.
Color can evoke emotion or symbolically represent aspects of culture or society. Complimentary colors may create contrast,
while analogous colors create harmony. Monochromatic colors demonstrate variations of a single color using various tints and shades.
Colors may be cool or warm.

Seven Elements of Design | eHow http://www.ehow.com/list_7676900_seven-elements-design.html#ixzz2UGsAKWp1