Dark Reaper vs N3 Neutral Gray

How close are they?

ΔE 10.0, close: similar, with a visible difference side by side. N3 Neutral Gray is more muted than Dark Reaper.

Can I use N3 Neutral Gray instead of Dark Reaper?

Usually, if you are not matching paint already on the model. Close match (ΔE 10). N3 Neutral Gray is more muted than Dark Reaper.

Can I use Dark Reaper instead of N3 Neutral Gray?

The same difference applies the other way round: Dark Reaper is more saturated.

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.