How does “Crayola color wonder mess free” clear gel paint work?


The “paint” is a clear gel with 6 distinct colors. When the gel is applied to trademarked paper, it turns the appropriate color. Is the color change due to a reaction with paper medium, oxidation as the gel dries, a combo of both or witchcraft?

In: 2

It uses Leuco Dye iirc, which is a thermo/photo/halochromism reaction, either the temp, light or ph balance changes allowing the actual color to appear.

My guess is it’s halochromism as color changes via pH changes with water mix would allow multiple colors. Where light would be one color and obviously thermo would require temperature changes. Each pen has a certain pH level and allows the appropriate color to appear when applied to the paper as it is offset by the papers pH level. Kinda like how urine test strips work.