Eshin Grey vs Nocturne Skin

How close are they?

ΔE 15.2, loose: different enough that you should pick on purpose. Nocturne Skin is a little darker, much more saturated than Eshin Grey.

Can I use Nocturne Skin instead of Eshin Grey?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 15). Nocturne Skin is a little darker, much more saturated than Eshin Grey.

Can I use Eshin Grey instead of Nocturne Skin?

The same difference applies the other way round: Eshin Grey is a little lighter, much more muted.

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.