ΔE 12.1, fair: the same colour family, but not a straight swap. Vermilion is a little lighter, more saturated, warmer than Blood Thorn.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 12). Vermilion is a little lighter, more saturated, warmer than Blood Thorn.
The same difference applies the other way round: Blood Thorn is a little darker, 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 Blood Thorn on the colour wheel See Vermilion on the colour wheel
All matches: Blood Thorn equivalents · Vermilion equivalents