ΔE 11.4, fair: the same colour family, but not a straight swap. Yellow RLM04 is a little darker, more muted than RLM 04.
✓ AK 3rd Generation equivalence chart lists these two as equivalents.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 11). Yellow RLM04 is a little darker, more muted than RLM 04.
The same difference applies the other way round: RLM 04 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 RLM 04 on the colour wheel See Yellow RLM04 on the colour wheel
All matches: RLM 04 equivalents · Yellow RLM04 equivalents