ΔE 12.4, fair: the same colour family, but not a straight swap. Royal Cloak is a little lighter, more muted, cooler than Bootstrap Brown.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 12). Royal Cloak is a little lighter, more muted, cooler than Bootstrap Brown.
The same difference applies the other way round: Bootstrap Brown is a little darker, more saturated, 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 Bootstrap Brown on the colour wheel See Royal Cloak on the colour wheel
All matches: Bootstrap Brown equivalents · Royal Cloak equivalents