ΔE 13.2, fair: the same colour family, but not a straight swap. Dark Turquoise is noticeably darker than Nighthaunt Gloom.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 13). Dark Turquoise is noticeably darker than Nighthaunt Gloom.
The same difference applies the other way round: Nighthaunt Gloom is noticeably lighter.
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 Nighthaunt Gloom on the colour wheel See Dark Turquoise on the colour wheel
All matches: Nighthaunt Gloom equivalents · Dark Turquoise equivalents