Package - ggthemes
Novelty - Yes
Type - qualitative

ggthemes - Seattle_Grays

Github

jrnold/ggthemes

CRAN

ggthemes

Use with paletteer package:

library(paletteer)
paletteer_d("ggthemes::Seattle_Grays")

Use raw:

c("#767F8BFF", "#B3B7B8FF", "#5C6068FF", "#D3D3D3FF", "#989CA3FF")