Modifying the exterior of your car is a big commitment. Either you’re applying new paint, which is a pretty permanent change, or you’re installing stickers or a wrap, which takes time, money, and effort. If you end up not liking the finished product, you can’t just flip a switch and turn your car back to how it was before, or get a refund.

That is, unless you have a Porsche with this new color-changing exterior film. The German luxury car maker recently submitted a patent application to the World Intellectual Property Organization (WIPO), describing a material installed on the exterior panel of a car that, when an electronic voltage is applied, changes colors.

Porsche, being the maker of the iconic 911, decided it would be best to use this technology as a way to incorporate racing stripes on demand. The patent application describes the film as changing colors to make racing stripes appear on the hood, roof, and rear decklid when the car is placed into a different drive mode. But Porsche also says it can be used as a way to display an EV’s state of charge, allowing drivers to simply glance at the car’s exterior to see whether it’s charged up enough to drive.

The patent application describes this film as “electronic paper” or “paramagnetic coatings,” which can alter their appearance based on how many volts are running through them.

This tech isn’t exactly new. Companies like Porsche, Audi, McLaren, and Mercedes-Benz use a similar type of coating in sunroofs to adjust the amount of sunlight coming through the glass. In Porsches, this feature is called “Variable Light Control.”

Where this patent application differs is in how the film is used. Instead of on glass, the electronically charged film is placed on body panels, and, in the case of Porsche’s example, patterned to show a set of racing stripes running down the center line of the car’s exterior.

In normal driving mode, these stripes are invisible. But when the drive mode is switched, they appear out of thin air. Porsche describes the stripes as “rally stripes,” and also predicts the film could be used to distinguish cars in a race, which feels a bit more practical than someone trying to trick people into thinking they own multiple Porsches.

In the case of a road car, the stripes aren’t the only thing that would appear. In an additional drawing, Porsche describes how the sideblade panels behind the rear wheels and the diffuser area could also change color when placed into sport mode, highlighting the car’s sportiest elements to the public.

Adding or deleting fancy stripes from your Carrera Cup car isn’t the only way Porsche proposes this film could be used on the exterior body panels. The company also positions it as an external display of the car’s current state of charge.

Basically, the film would use a computer to signal how much charge the car’s battery has, and display that on a piece of body panel, “such that the color of the coating depends on the current state of charge,” according to the patent application.

So, for example, if the film is showing red, that means the battery isn’t charged. But if it’s showing green, that means the car is charged up and ready to drive. And if it’s showing yellow, it’s somewhere in the middle.

While this all sounds like pretty advanced, expensive tech, Porsche points out in the patent application that it’s not too far from reality:

It is considered particularly advantageous to modify the optical appearance of the coating using electrophoresis. The advantage lies in the relatively low energy consumption required to change the color. Furthermore, when modifying the optical appearance via electrophoresis, especially the change in the outer color, it is possible to design the modification in such a way that electrical energy is required to effect a change in the state of the outer color, but no electrical energy, or only a significantly lower amount, is required to maintain the existing state.

Of course, there’s no telling whether color-changing film will ever make it to a Porsche production car, or even a Porsche race car. Many pieces of tech found in patent applications never see the light of day. In this case, though, it seems there are at least a few practical reasons for this to actually exist in the real world. What would you use this color-changing film for? Let me know in the comments, I’m curious to hear what you think.