Raspberry Pis use a mobile multimedia processor known as VideoCore, owned by Broadcom. The VideoCore dev team has a small tradition of rendering an RGB triangle when developing new projects. The new Vulkan driver for the Pi is no exception!
The driver might not be available yet, but the Igalia team has made some serious progress. A screenshot posted by Eben Upton on January 31st shows the perfectly rendered RGB triangle created with VideoCore VI Vulkan.
The development process is still in the early stages. As exciting as it is to see progress, it may be a while before you can download Vulkan for your Raspberry Pi. Eben Upton said in his blog post, "Igalia has only been working on this new driver for a few weeks, and we still have a very long development roadmap ahead of us before we can put an actual driver in the hands of our users."