Definition

Variegation is pattern of two or more colors in a plant part, as in a green and white leaf. 

Etymology. "to mark with different colors," 1646 (implied in variegation), from L.L. variegatus "made of various sorts or colors," pp. of variegare "diversify with different colors," from varius "spotted, changing, varying" (vary) + root of agere "to drive".

Discussion

Variegation of plant foliage may be naturally occurring, or arising from genetic mutaiton, or caused by plant disease.