I have a slight color deficiency, so the sample formula and paragraph are a bit hard to read for me, especially the paragraph. Up to 8% of male adults suffer from this, at various levels, so I'm surprised the authors did not mention this problem.

Another point is that their choice of colors seems to mix various luminosity levels. So I suppose that, even for someone without color blindness, some colored texts are are much more visible than others. I doubt this hierarchy was intended.