Very nice deep dive into the data!
I find it very curious that many of the national curves have very sharp, flat-topped "peaks" of about a week's duration. Do you know of an explanation for this feature? I suspect that they are reporting errors, and it would be useful to know their origin and appropriate data-cleaning techniques.
I've been using ColorData for many years, and learned something new about it today: one can get the colors reversed directly with
ColorData[{"RedBlueTones","Reversed"}][#]&