metachromasia

noun

meta·​chro·​ma·​sia ˌmet-ə-krō-ˈmā-zh(ē-)ə 

1

: the property of various tissues of staining in a different color (as when treatment with a blue aniline dye makes a cellular element red)

2

: the property of various biological stains that permits a single dye to stain different tissue elements in different colors