Color changing inks are inks containing pearlescent pigments that change color when viewed at a different angle. The color of the
ink does not actually change, but the angle of the light to the viewer's eye changes and thus creates the change in color. A
number of types are available, including green to purple, gold to green and green to lilac.
What's more,Optically variable ink is an anti-counterfeiting measure used on many major modern banknotes.
The ink displays two distinct colors depending on the angle the bill is viewed at. The United States fifty-dollar bill, for
example, uses color shifting ink for the numeral 50 so that it displays copper at one angle and bright green in another.
Optically variable ink is particularly useful as an anti-counterfeiting measure as it is not widely available; the major
manufacturer is a Swiss company called SICPA (Société Industrielle et Commerciale de Produits pour l'Agriculture), as well can be
supplied by Sun Chemical, through their Brand Protection Division based in Manchester, UK.
Color
Series A: purple to green,green to purple,green to orange,green to blue,blue to purple.
Series B: gold to green ,red to gold, blue to purple red , blue green to purple, green to blue.
Series C: colorless to purple,colorless to green , colorless toblue, colorless to gold.
Series F: brown to purple,colorless to green, colorless to blue,colorless to gold, magenta to gold, gold to green, rose red to
gold, yellow green to blue, blue green to purple.