ΔE 10.3, fair: the same colour family, but not a straight swap. Desert Yellow is a little lighter, cooler than RAL 8031 F9 Sandbraun.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 10). Desert Yellow is a little lighter, cooler than RAL 8031 F9 Sandbraun.
The same difference applies the other way round: RAL 8031 F9 Sandbraun is a little darker, 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 RAL 8031 F9 Sandbraun on the colour wheel See Desert Yellow on the colour wheel
All matches: RAL 8031 F9 Sandbraun equivalents · Desert Yellow equivalents