Occultist Cloak vs Basilicanum Grey

How close are they?

ΔE 17.1, loose: different enough that you should pick on purpose. Basilicanum Grey is noticeably lighter, more muted than Occultist Cloak.

Can I use Basilicanum Grey instead of Occultist Cloak?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 17). Basilicanum Grey is noticeably lighter, more muted than Occultist Cloak.

Can I use Occultist Cloak instead of Basilicanum Grey?

The same difference applies the other way round: Occultist Cloak is noticeably darker, 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.