Building off of its previously developed ColorMod system, MIT's Computer Science and Artificial Intelligence Laboratory (CSAIL) created PhotoChromeleon Ink, which allows the color or pattern of an object to be altered when exposed to UV light. While there are plenty of color-changing products on the market, this "reprogrammable ink" can be sprayed onto a variety of objects to change how they look.
After something like a phone, a shoe, a phone case or a toy has been treated with PhotoChromeleon Ink, it is placed in a box with a projector and UV light to activate and deactivate different colors. Once removed from the box, the colors maintain their appearance in natural light, yet they can be changed time and time again when exposed to UV light.
MIT's PhotoChromeleon Ink Creates Customizable Objects
Laura McQuarrie — September 11, 2019 — Tech
References: news.mit.edu & engadget