It’s not like Apple to kill a lucrative revenue stream for no reason, but the company may have ambitious plans up its figurative sleeve for what sits under your literal one.

A newly-granted patent spotted by AppleInsider shows that the company is considering the possibility of an Apple Watch strap that changes colour to your liking, doing away with the need to buy lots of different accessories for your wearable. 

It’s taking inspiration with the chameleon, in other words, with an accessory that can colour-match your outfit without you having to clip on a whole new strap.

“Users may desire the ability to customise their watch bands to express variety and style,” the patent reads. “For example, a user may desire a watch band of a particular coluor based on the user’s selection of clothing, other wearable articles, environment, or another preference,” it continues, just in case the reader is an alien unfamiliar with human concepts like fashion.

The patent’s answer to this is a Watch band with “electrochromic features,” where “an applied voltage” allows “a variety of colours and colour combinations to be displayed by a single band.” It would do this with fabric that’s woven around filaments that can “include a conductor and an electrochromic layer”, Apple explains.

“The electrochromic layer can be electrically connected to the conductor so that voltage applied to the conductor is communicated to the electrochromic layer,” it continues. 

While some people will feel squeamish with talk of voltages being applied on their wrists in the name of fashion, there are other more practical uses for the technology. 

The patent suggests that the Apple Watch itself could trigger a colour change to get your attention instead of a notification. It could turn green when you fill an activity ring, for example, or flash blue when you get a WhatsApp message. It could even be used to “display particular icons, shapes and/or text by illuminating certain elements in a particular way.” Fancy.

It all sounds very advanced, and hard for third parties to copy. Perhaps that’s the reason Apple is considering it: if people are buying cheap third-party watch straps, then maybe one very expensive must-have accessory is the way to win them back. Because Apple being Apple, this will be expensive.

How expensive? We’ll have to see if this ever becomes anything more than a theoretical patent.