ΔE 14.2, fair: the same colour family, but not a straight swap. Sand Yellow RLM79 is a little lighter, much more muted, cooler than Warm Brown.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 14). Sand Yellow RLM79 is a little lighter, much more muted, cooler than Warm Brown.
The same difference applies the other way round: Warm Brown is a little darker, much 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 Warm Brown on the colour wheel See Sand Yellow RLM79 on the colour wheel
All matches: Warm Brown equivalents · Sand Yellow RLM79 equivalents