ΔE 8.5, close: similar, with a visible difference side by side. Royal Brown is a little darker, cooler than Husk Brown.
Usually, if you are not matching paint already on the model. Close match (ΔE 9). Royal Brown is a little darker, cooler than Husk Brown.
The same difference applies the other way round: Husk Brown is a little lighter, warmer.
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 Husk Brown on the colour wheel See Royal Brown on the colour wheel
All matches: Husk Brown equivalents · Royal Brown equivalents