ΔE 9.0, close: similar, with a visible difference side by side. Nighthaunt Gloom is more saturated, warmer than Runic Grey.
Usually, if you are not matching paint already on the model. Close match (ΔE 9). Nighthaunt Gloom is more saturated, warmer than Runic Grey.
The same difference applies the other way round: Runic Grey is more muted, cooler.
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 Runic Grey on the colour wheel See Nighthaunt Gloom on the colour wheel
All matches: Runic Grey equivalents · Nighthaunt Gloom equivalents