Package - ggthemes
Novelty - Yes
Type - qualitative
ggthemes - Seattle_Grays
Use with paletteer package:
library(paletteer)
paletteer_d("ggthemes::Seattle_Grays")
Use raw:
c("#767F8BFF", "#B3B7B8FF", "#5C6068FF", "#D3D3D3FF", "#989CA3FF")