ΔE 10.3, fair: the same colour family, but not a straight swap. Buff is a little darker, more muted than Barren Dune.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 10). Buff is a little darker, more muted than Barren Dune.
The same difference applies the other way round: Barren Dune is a little lighter, more saturated.
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 Barren Dune on the colour wheel See Buff on the colour wheel
All matches: Barren Dune equivalents · Buff equivalents