ΔE 9.7, close: similar, with a visible difference side by side. Naphthol Red Light is a little lighter, more saturated than Fiery Vermilion.
Usually, if you are not matching paint already on the model. Close match (ΔE 10). Naphthol Red Light is a little lighter, more saturated than Fiery Vermilion.
The same difference applies the other way round: Fiery Vermilion is a little darker, more muted.
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 Fiery Vermilion on the colour wheel See Naphthol Red Light on the colour wheel
All matches: Fiery Vermilion equivalents · Naphthol Red Light equivalents