ΔE 9.5, close: similar, with a visible difference side by side. US Earth Red is more muted than Graveyard Earth.
Usually, if you are not matching paint already on the model. Close match (ΔE 10). US Earth Red is more muted than Graveyard Earth.
The same difference applies the other way round: Graveyard Earth is more saturated.
ΔE is the colour difference between our two swatch estimates: under about 6 is close, over about 15 is loose. Real paints also differ in finish, coverage and how they thin, so test before you commit.
See Graveyard Earth on the colour wheel See US Earth Red on the colour wheel
All matches: Graveyard Earth equivalents · US Earth Red equivalents