ΔE 12.5, fair: the same colour family, but not a straight swap. Bright Brown Grey is a little darker, more muted, warmer than Tomb King Tan.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 13). Bright Brown Grey is a little darker, more muted, warmer than Tomb King Tan.
The same difference applies the other way round: Tomb King Tan is a little lighter, more saturated, cooler.
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 Tomb King Tan on the colour wheel See Bright Brown Grey on the colour wheel
All matches: Tomb King Tan equivalents · Bright Brown Grey equivalents