ΔE 6.8, close: similar, with a visible difference side by side. Sand Brown is a little darker, cooler than Boot Strap Brown.
Usually, if you are not matching paint already on the model. Close match (ΔE 7). Sand Brown 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 Sand Brown on the colour wheel
All matches: Boot Strap Brown equivalents · Sand Brown equivalents