The choroplethr package is outstanding and fairly easy to use, but some functionality is not obvious. The built-in color scheme is quite good, but you might want to switch colors at some point. My first attempt at changing the color scheme can be found below (previous post has basic code for using choroplethr):
Pretty simple code – just adding a scale_fill_brewer() command. This gets you most of the way there, but frustratingly AK is still in the original color scheme.
Here is how you can actually change the color scheme:
Voila! All the colors are changed to the new scheme!
Full R code: