I agree, but I found the first half much more useful (so far) than the last half. The second half was honestly a little overwhelming it what it felt like it was assuming about my capabilities. Less of "this small change or some slight variation will help a lot" and more "use your design experience to choose something visually pleasing here", which honestly, the lack of such experience is why I was reading such a guide.

For me it started being less legible after the font change to Arial and kept going downhill from there.

At the point where the contrast of the text was reduced, I was off the hook. I'd rather do that the way OP did, by changing the background to a pleasant pastel. Either way, I'm impressed with the format.