Why did author decide that best way to demonstrate his idea would be by cutting contrast in half?
color-coding might be a great solution, but you don't really know beforehand which byte values are important. Manually selecting C0 to make it stand out it just ctrl+f with extra steps. (But I wouldn't mind something like "color 00 separate from ascii separate from the rest)
> Manually selecting C0 to make it stand out
That's not what they did, actually. C0 is the only byte in there that's above 3F or so, and it's far from it. Hence the very different colour, and the lack of contrast between the colours of the other bytes.