ΔE 12.6, fair: the same colour family, but not a straight swap. Ember Orange is a little lighter, more saturated than Pure Red.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 13). Ember Orange is a little lighter, more saturated than Pure Red.
The same difference applies the other way round: Pure Red is a little darker, more muted.
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 Pure Red on the colour wheel See Ember Orange on the colour wheel
All matches: Pure Red equivalents · Ember Orange equivalents