metachromasia

[mĕt′ə-krō-māzhə]
n.
  1. The characteristic of a cell or tissue component of taking on a color different from that of the dye with which it is stained.
  2. The property of certain dyes to stain different substances different colors.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.