> > A somewhat related question - colour fonts are used beyond > > emoji's. While there are 5 kinds of emoji fonts now, and most > > people are using one of 4... but if you check Google Fonts, there > > are 10 colour fonts, one is emoji, but 6 are Arabic (useful for > > annotating the Quran...) and 3 are Latin. So there are intentions > > for text fonts. A few percents of western male population is > > color-blind. Colour-blindness is one of the most common eye > > problems, after short-sightedness :-). > > I’m colour-blind, but not sure I understand what you’re asking > here. None of the colour fonts on Google Fonts seem obviously > difficult to read for me.
Let's assume that you can't discern colors A and B, where both map to exactly the same gray value C (or to almost identical values). If a glyph uses those two colours exclusively, you will have problems with both a colour and a gray-level version of it. Werner