It's not easy to make crisp coloured epoxy inlays in wood as the fluid epoxy tends to bleed into the wood grain.
I've tried a lot of methods and found the one that gives the best results for me. Here it is!
My CNC is an Aureus 3X from Euro Makers, similar to a Shapeoko or an X-Carve: https://euro-makers.com/fr/381-cnc-aureus-3x
3.175 15° tapered bit: https://www.aliexpress.com/item/4000496864598.html?spm=a2g0s.9042311.0.0.f79a4c4dOonOVb
2mm straight bit: https://amzn.to/33e6q56
Clear epoxy: https://amzn.to/2Zv0tjl
5-minute epoxy: https://amzn.to/3hj8Vs9