PURPOSE: To enable the free setting of discoloration temp. and to make it possible to use electron donating coloration dyes over a wide range, by constituting the titled color material of three components, that is, electron donating coloration dyes, castor oil or hardened castor oil and inorg. or org. acid ester of castor oil or hardened castor oil.

CONSTITUTION: The titled color material is constituted of three components, that is, electron donating coloration dyes, castor oil or hardened castor oil and inorg. or org. acid ester of castor oil or hardened oil. The OH group of castor oil or hardened castor oil acts of a coloring factor and a discoloration temp. determining factor. As the discoloration temp. determining factor, the m.p. or solidification point of hardened castor oil can be freely altered by hydrogenation quantity. Because castor oil or hardened castor oil has not only oleophilicity but also hydrophilicity, said oil easily dissolves various org. compounds of the electron donating coloration dyes and has good compatibility with inorg. or org. acid ester or partial ester of castor oil or hardened castor oil of the same component system. By this method, discoloration temp. can be freely set, and discoloration sensitivity and color sharpness are excellent.