Instructables user Greeegification showcasing his rainbow ring wall clock:
" I don't know what it is about clocks and watches, but it seems that every second projects is one form of the two. This project follows along in the footsteps too. I have made smaller clocks before, but nothing of the scale of a typical wall clock. This is due mainly to the high price of fabricating one off large PCBs.
I wanted to create something large, not too big. I also wanted to keep the cost down. I managed to solve these problems by making various design choices, which will be covered in detail in the following steps.
I got some initial inspiration from adafruits 12 pixel neopixel ring, and now I notice that they sell a 60 pixel version which wasn't available back when I designed this, but comes as 4 segments to create a full ring. This would be an easy way to create a similar clock, without the need for making PCBs and soldering LEDs and small SMD parts."