ΔE 33.6, loose: different enough that you should pick on purpose. Green Ghost is noticeably darker, much more muted, warmer than Ghoul Green.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 34). Green Ghost is noticeably darker, much more muted, warmer than Ghoul Green.
The same difference applies the other way round: Ghoul Green is noticeably lighter, much more saturated, cooler.
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 Ghoul Green on the colour wheel See Green Ghost on the colour wheel
All matches: Ghoul Green equivalents · Green Ghost equivalents