I thought about nesting level coloring but had never seen it in action. I just look at it and it indeed looks nice.

I thought it would be interesting as it separates that what repeats a task from the actual work being done on it.

More nesting suggests more complexity.

In my experiments I notice different ways to write something look better with different kinds of highlighting.

If you for example use no highlights dividing the logic over tiny functions looks quite readable.

In one experiment I use dark colors on a black background with only the comments in bright white. I wrote a lot more comments using that. Everything had a description and I could gaze over it as if the code wasn't there.