Occultist Cloak vs Green Stone

How close are they?

ΔE 16.5, loose: different enough that you should pick on purpose. Green Stone is a little darker, more muted than Occultist Cloak.

Can I use Green Stone instead of Occultist Cloak?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 16). Green Stone is a little darker, more muted than Occultist Cloak.

Can I use Occultist Cloak instead of Green Stone?

The same difference applies the other way round: Occultist Cloak is a little 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.