ΔE 13.1, fair: the same colour family, but not a straight swap. Darkness is noticeably darker, more saturated than Eshin Grey.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 13). Darkness is noticeably darker, more saturated than Eshin Grey.
The same difference applies the other way round: Eshin Grey is noticeably lighter, 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.
See Eshin Grey on the colour wheel See Darkness on the colour wheel
All matches: Eshin Grey equivalents · Darkness equivalents