Github
jrnold/ggthemes
CRAN
ggthemes
Use with paletteer package:
library(paletteer) paletteer_d("ggthemes::excel_Grayscale")
Use raw:
c("#DDDDDDFF", "#B2B2B2FF", "#969696FF", "#808080FF", "#5F5F5FFF", "#4D4D4DFF")