The Collaborative International Dictionary of English v.0.48:

Discolor \Dis*col"or\, v. t. [imp. & p. p. Discolored; p. pr.
   & vb. n. Discoloring.] [OE. descolouren, OF. descolorer, F.
   d['e]colorer, fr. L. dis- + cololare, coloratum, to color,
   color color. See Color.] [Written also discolour.]
   1. To alter the natural hue or color of; to change to a
      different color; to stain; to tinge; as, a drop of wine
      will discolor water; silver is discolored by sea water.
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   2. To alter the true complexion or appearance of; to put a
      false hue upon.
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            To discolor all your ideas.           --Watts.
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