ΔE 11.6, fair: the same colour family, but not a straight swap. Daemonette Hide is a little darker, more saturated than RAF Dark Sea Grey BS381C/638.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 12). Daemonette Hide is a little darker, more saturated than RAF Dark Sea Grey BS381C/638.
The same difference applies the other way round: RAF Dark Sea Grey BS381C/638 is a little 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 RAF Dark Sea Grey BS381C/638 on the colour wheel See Daemonette Hide on the colour wheel
All matches: RAF Dark Sea Grey BS381C/638 equivalents · Daemonette Hide equivalents