ggplot colors - SERP Analysis

https://sape.inf.usi.ch/quick-reference/ggplot2/colour

https://r-graph-gallery.com/ggplot2-color.html

http://cookbook-r.com/Graphs/Colors_(ggplot2)/

https://ggplot2.tidyverse.org/reference/aes_colour_fill_alpha.html

https://www.sthda.com/english/wiki/ggplot2-colors-how-to-change-colors-automatically-and-manually