metachromatism

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A change in color caused by variation of the physical conditions to which a body is subjected, especially such a change caused by variation in temperature.

from The Century Dictionary.

• noun Change of color; specifically, variation of color due to changes in the temperature of a body; change of color by change of physical conditions, as in the case of a double salt consisting of silver chlorid and mercuric iodide, which changes from yellow to red on being heated and returns to yellow after cooling.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun metachromasia