ΔE 8.9, close: similar, with a visible difference side by side. Rifle Brown is more muted, warmer than Cardinal Purple.
Usually, if you are not matching paint already on the model. Close match (ΔE 9). Rifle Brown is more muted, warmer than Cardinal Purple.
The same difference applies the other way round: Cardinal Purple is more saturated, 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 Cardinal Purple on the colour wheel See Rifle Brown on the colour wheel
All matches: Cardinal Purple equivalents · Rifle Brown equivalents