ΔE 13.3, fair: the same colour family, but not a straight swap. Light Emerald is a little lighter, more muted, cooler than Eldritch.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 13). Light Emerald is a little lighter, more muted, cooler than Eldritch.
The same difference applies the other way round: Eldritch is a little darker, more saturated, 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.
See Eldritch on the colour wheel See Light Emerald on the colour wheel
All matches: Eldritch equivalents · Light Emerald equivalents