Occultist Cloak vs Dark Green Blue

How close are they?

ΔE 17.9, loose: different enough that you should pick on purpose. Dark Green Blue is a little darker, more saturated, cooler than Occultist Cloak.

Can I use Dark Green Blue instead of Occultist Cloak?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 18). Dark Green Blue is a little darker, more saturated, cooler than Occultist Cloak.

Can I use Occultist Cloak instead of Dark Green Blue?

The same difference applies the other way round: Occultist Cloak is a little lighter, more muted, 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.