ΔE 6.9, close: similar, with a visible difference side by side. Vermilion is a little lighter than Alizarin Crimson.
Usually, if you are not matching paint already on the model. Close match (ΔE 7). Vermilion is a little lighter than Alizarin Crimson.
The same difference applies the other way round: Alizarin Crimson is a little darker.
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 Alizarin Crimson on the colour wheel See Vermilion on the colour wheel
All matches: Alizarin Crimson equivalents · Vermilion equivalents