I helped Dutch typographer Novo Typo to convert their Bixa font to a color version. I chose the SVG-in-OpenType format and decided to see how "web worthy" I could make such a font, meaning it had to be small and not obscure the text when SVG-in-OpenType isn't supported. (Spoiler: only Firefox supports it right now!)
The nerdy techy write-up is here:
https://pixelambacht.nl/2016/building-bixa-color/Part of this project is ChromaCheck, a small feature test to see if any of the four color font formats are supported in a browser:
https://github.com/RoelN/ChromaCheckI hope you find this interesting. If you have any questions, do ask!