ΔE 6.1, close: similar, with a visible difference side by side. Mustard Brown is more saturated than Boot Strap Brown.
Usually, if you are not matching paint already on the model. Close match (ΔE 6). Mustard Brown is more saturated than Boot Strap Brown.
The same difference applies the other way round: Boot Strap Brown is more muted.
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 Mustard Brown on the colour wheel
All matches: Boot Strap Brown equivalents · Mustard Brown equivalents