ΔE 7.9, close: similar, with a visible difference side by side. Brown Violet RLM81 is more muted than Venom Wyrm.
Usually, if you are not matching paint already on the model. Close match (ΔE 8). Brown Violet RLM81 is more muted than Venom Wyrm.
The same difference applies the other way round: Venom Wyrm is 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 Venom Wyrm on the colour wheel See Brown Violet RLM81 on the colour wheel
All matches: Venom Wyrm equivalents · Brown Violet RLM81 equivalents