ΔE 6.4, close: similar, with a visible difference side by side. Field Gray 1 is cooler than Dark Reaper.
Usually, if you are not matching paint already on the model. Close match (ΔE 6). Field Gray 1 is cooler than Dark Reaper.
The same difference applies the other way round: Dark Reaper is warmer.
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 Dark Reaper on the colour wheel See Field Gray 1 on the colour wheel
All matches: Dark Reaper equivalents · Field Gray 1 equivalents