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