An interview with OnePlus' industrial design team was published to the company's forums earlier today, and though most of it is the sort of self-praise and directed discussion you'd expect to read, one genuinely interesting tidbit was revealed: Two photos of an unreleased OnePlus Concept One prototype. That's right, concept phones also have prototypes, and one of OnePlus' earlier efforts to design a phone in collaboration with McLaren was an all-black design.

This is the sort of thing that gets Marques Brownlee's blood pumping

The two images show the same Concept One we saw before, presumably including the variably transparent electrochromic glass, but this time swathed in a more roughly textured pebble-grain black leather, matching the black glass stripe down the center back, and highlighted by what looks like black carbon fiber (or a mock finish) between the camera assemblies under the glass. The look is fully monochrome, including what is either a silver or dark gray finish to the aluminum sides.

It's an understated appearance compared to the exceptionally orange concept phone the company showed us at CES — not that the distinction matters much since you can't actually buy either. Still, even concept phones have to be prototyped, and OnePlus went through at least one attractive color combination before it and McLaren finally settled on Cheeto.