ΔE 21.9, loose: different enough that you should pick on purpose. AMT-7 Greyish Blue is noticeably lighter, cooler than Coal Black.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 22). AMT-7 Greyish Blue is noticeably lighter, cooler than Coal Black.
The same difference applies the other way round: Coal Black is noticeably darker, warmer.
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 Coal Black on the colour wheel See AMT-7 Greyish Blue on the colour wheel
All matches: Coal Black equivalents · AMT-7 Greyish Blue equivalents