What if your Apple Watch could always match your outfit?

The Apple Watch already offers quite a lot of customisability. There's a wide array of straps on the market, both Apple's own and third-party options, and you can choose from a range of changeable digital faces. But while we wait for the launch of Apple Watch Series 9, it seems that Apple might be planning to take customisation much further in future devices.

The tech giant has filed a new patent with the US Patent and Trademark Office (USPTO) that describes sensors that would allow the Apple Watch to measure the colour of objects around it. These could be used to allow it to match the background of the watch face with the wearer's clothing or with the watch strap (see our guide the Apple Watch generations to see how the current lineup stands).

The USPTO patent filing entitled Electronic Devices with Color Sampling Sensors mentions watches only as an example use, and it's possible that the same concept could be applied to other devices, but the examples given focus very clearly on smartwatches. 

Apple says that optical sensors such as a camera, proximity sensor, ambient light sensor, fingerprint sensor, or other light-based sensor under a device's display could sample colours by emitting a sequence of red, green, and blue light at an object put in its line of sight and then measuring RGB reflectance levels.

The device's circuitry would apply a watch band-specific algorithm to the colour sample to match it with a predetermined list of colours and a clothing-specific algorithm to place the clothing within a specific colour gamut. After applying constraints, it would then mimic the sampled colour on the background of the device's display.

Don't expect to see this technology in Apple Watch Series 9, which will presumably be announced next month. The vast majority of Apple patents don't make their way into use, but the fact that this one gives details such a relatively concrete example of its use suggests that it may be something that Apple is seriously considering for Apple Watches a few years down the line.

As for what we can expect from Apple Watch 9, there has been a notable lack of rumours around this year's iteration. That might mean that it turns out to be a small update on last year's Series 8 (see the best Apple Watch Series 8 prices below). However, we've heard some troubling rumours about the design of a special anniversary edition Apple Watch X for next year, with it potentially featuring a new way to attach straps.