The Collaborative International Dictionary of English v.0.48:

Variegate \Va"ri*e*gate\, v. t. [imp. & p. p. Variegated; p.
   pr. & vb. n. Variegating.] [L. variegatus, p. p. of
   variegare to variegate; varius various + agere to move, make.
   See Various, and Agent.]
   To diversify in external appearance; to mark with different
   colors; to dapple; to streak; as, to variegate a floor with
   marble of different colors.
   [1913 Webster]

         The shells are filled with a white spar, which
         variegates and adds to the beauty of the stone.
                                                  --Woodward.
   [1913 Webster]

WordNet (r) 3.0 (2006):

variegate
    v 1: change the appearance of, especially by marking with
         different colors
    2: make something more diverse and varied; "Vary the menu" [syn:
       vary, variegate, motley]