> > 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.
Population health statistics - a few percent of Caucasian males are red-green colour-blind. I guess Brad is one of them. So I draw a pink smiley face on a pale green background, you won't be able to tell there is a smiley face.