ΔE 10.6, fair: the same colour family, but not a straight swap. Faded Red is a little lighter, warmer than Emperor Red.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 11). Faded Red is a little lighter, warmer than Emperor Red.
The same difference applies the other way round: Emperor Red is a little darker, 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 Emperor Red on the colour wheel See Faded Red on the colour wheel
All matches: Emperor Red equivalents · Faded Red equivalents