This Color-Changing Dye Lets You Swap Hues in Minutes

We love to express ourselves through colors, patterns, and images, from our clothes and our cars, to our cell phones and the water bottles that we take to the gym. But unless you have some serious DIY painting skills, you are stuck with whatever color an item was when you bought it. More than one person has upgraded to the latest iPhone simply because it was available in an exciting new color. But imagine if you could change the color or even image on your iPhone's case whenever you wanted. That is exactly what this new "ChromoUpdate" color-changing dye allows.

ChromoUpdate dye was developed by researchers from MIT and is an evolution of the PhotoChromeleon dye that covered a couple of years ago. This dye works similarly to those plastic cups that change color in response to the temperature of whatever beverage they contain. The difference is that this dye can be set to a wide range colors according to UV light exposure, and the color changes are semi-permanent. It is even possible to set the colors on a pixel-by-pixel basis, so images and patterns appear onto surfaces coated in the ChromoUpdate dye.

Like the PhotoChromeleon dye, the ChromoUpdate dye contains cyan, magenta, and yellow pigments. Exposure to UV light causes those pigments to become completely saturated, so the overall color is close to white. Selective exposure to visible light then desaturates each pigment until it reaches the desired color. This process took about 20 minutes for PhotoChromeleon dye, but only takes a few minutes for ChromoUpdate — or mere seconds for a grayscale preview image. In the time it takes to microwave some ramen noodles, users can completely change the appearance of any object coated in ChromoUpdate dye.

The color-changing process is faster for ChromoUpdate thanks to the use of a special UV light projector, similar to the kind that you would find in a resin 3D printer. The process for saturating PhotoChromeleon dye utilized UV LEDs, which shone across the entire surface. The use of the UV projector means individual pixels can be selectively saturated as well as selectively desaturated, making it unnecessary to recolor the entire surface.

This process is repeatable, so it is possible to recolor objects dyed with ChromoUpdate many times. Unfortunately, because the dye desaturates when exposed to visible light and saturates in UV light, images and colors will presumably degrade over time under normal conditions. That means that ChromoUpdate is most suitable for prototyping and likely won't be coating your iPhone anytime soon, though future tweaks to the formula may change that.