As per note that shows when you hold the mouse over the “color font” option, support varies - for these to semi-consistently show up across major browsers, you need to supply 4 (!) different color font formats, and the library that I use to generate the final TTF/OTF fonts only implements one.
First of all, don’t forget to switch Glyph Color to Color Font on the first tab.
The tool uses the fonthx library, which generates color fonts in embedded SVG format. On my devices:
- Windows & Linux: color fonts show in Firefox (and Firefox-based browsers), but not in Chromium-based browsers
- iOS: color fonts show in all browsers as it’s all Safari anyway