Color-change marking system

Abstract

The marking system includes one or more ink compositions and a color-change agent composition. The ink composition applied to a substrate such that it is a first color, but when a color-change agent is applied, one or more secondary colors appear. The ink compositions each have a respective ink color and include a respective: at least one first dye composition having a respective first color and at least one second dye composition having a respective second color. The first dye composition can react with the color-change agent composition. When the color-change agent composition contacts the ink composition, each respective first dye composition reacts with the color-change agent composition, 10 thereby producing each respective second color. Each respective first color is different from each respective second color, and each respective second color is different from each respective ink color.

Dependencies are inferred from the claim text.