ΔE 6.3, close: similar, with a visible difference side by side. Purple Hex is more saturated, warmer than Crimson Hell.
Usually, if you are not matching paint already on the model. Close match (ΔE 6). Purple Hex is more saturated, warmer than Crimson Hell.
The same difference applies the other way round: Crimson Hell 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 Crimson Hell on the colour wheel See Purple Hex on the colour wheel
All matches: Crimson Hell equivalents · Purple Hex equivalents