Ember Orange vs Yellow RLM04

How close are they?

ΔE 11.7, fair: the same colour family, but not a straight swap. Yellow RLM04 is a little lighter, cooler than Ember Orange.

Can I use Yellow RLM04 instead of Ember Orange?

Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 12). Yellow RLM04 is a little lighter, cooler than Ember Orange.

Can I use Ember Orange instead of Yellow RLM04?

The same difference applies the other way round: Ember Orange 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.