ggthemes

theme_solid

Theme with nothing other than a background color

theme_few

Theme based on Few's "Practical Rules for Using Color in Charts"

theme_excel

ggplot color theme based on old Excel plots

gdocs_pal

Google Docs color palette (discrete)

few_pal

Color Palletes from Few's "Practical Rules for Using Color in Charts"

colorblind

Colorblind Color Palette (Discrete) and Scales

calc_pal

Calc color palette (discrete)