ΔE 8.7, close: similar, with a visible difference side by side. Naphthol Red Medium is a little darker, more muted than Archangel Red.
Usually, if you are not matching paint already on the model. Close match (ΔE 9). Naphthol Red Medium is a little darker, more muted than Archangel Red.
The same difference applies the other way round: Archangel Red is a little lighter, 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.
See Archangel Red on the colour wheel See Naphthol Red Medium on the colour wheel
All matches: Archangel Red equivalents · Naphthol Red Medium equivalents