ΔE 21.5, loose: different enough that you should pick on purpose. Yellow RLM04 is a little darker, much more saturated, warmer than Sandy Yellow.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 21). Yellow RLM04 is a little darker, much more saturated, warmer than Sandy Yellow.
The same difference applies the other way round: Sandy Yellow is a little lighter, much more muted, 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 Sandy Yellow on the colour wheel See Yellow RLM04 on the colour wheel
All matches: Sandy Yellow equivalents · Yellow RLM04 equivalents