Color changing inks were introduced during the 1970s with novelty items such as cups that change color when not liquids such as coffee or tea are poured in to them.
Color changes of thermo chromic pigments are induced by a temperature change. When temperature rises to a specific temperature, the color changes. The color starts fading back to the original color as the pigment is cooled down.
Application of thermo chromic color on garment:
There are fifteen thermo chromic colors like Americos Red, Magenta, Vermilion, Orange, Yellow, Yellow Green, Charm Green, Sky Blue, Turq Blue, Dark Blue, Violet, and Black. The temperature interval available from 0OC to 70OC. Specific demand can be set up for different temperature intervals from 2OC to 10OC.
By using the above colors another color can be obtained but use different colors of thermo chromic pigments with the same temperature range to create more colors. Regular pigments can also be mixed with thermo chromic pigment so that the color can be changed from one to another. At lower temperature, the color reveals matched shade. When the temperature is increased, the thermo chromic pigments start fading to colorless. It only shows color of the regular pigments. By mixing the thermo chromic pigments with different temperature ranges, the color can be varied for more than two colors like temperature ranges for 3 color variation.
These t-shirts and other garments can change color by wearing or touching them. The heat from your body, hand or the environment makes this clothing change color. Once cooled the fabric changes back to the original color.