Several Painting Schedules are below for Liberty Ships, with somewhat generic color call outs, as others have mentioned not using standardized USN colors.

The National Archives have at least four different copies of original Painting Schedules (plan S19-1-1) indicating a variety of shipyard applications:

All Exteriors above the 10’ line “Dark Gray, Low Visibility”:
https://catalog.archives.gov/id/118795036?objectPage=468
https://catalog.archives.gov/id/118791952?objectPage=570
Vertical Surfaces “Slate Gray Type I”, Horizontal Surfaces “Deck Gray Type I”:
https://catalog.archives.gov/id/118784671?objectPage=433
Vertical Surfaces “Slate Gray Type II”, Horizontal Surfaces “Deck Gray Type I”:
https://catalog.archives.gov/id/118772635?objectPage=401