ΔE 6.4, close: similar, with a visible difference side by side. Brown Sand is a little darker, cooler than Boot Strap Brown.
Usually, if you are not matching paint already on the model. Close match (ΔE 6). Brown Sand is a little darker, cooler than Boot Strap Brown.
The same difference applies the other way round: Boot Strap 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 Boot Strap Brown on the colour wheel See Brown Sand on the colour wheel
All matches: Boot Strap Brown equivalents · Brown Sand equivalents