ΔE 16.9, loose: different enough that you should pick on purpose. Greasy Black is noticeably darker, more muted than Graphite Green.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 17). Greasy Black is noticeably darker, more muted than Graphite Green.
The same difference applies the other way round: Graphite Green is noticeably lighter, 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 Graphite Green on the colour wheel See Greasy Black on the colour wheel
All matches: Graphite Green equivalents · Greasy Black equivalents