ΔE 14.2, fair: the same colour family, but not a straight swap. Deep Green is a little darker, more saturated, cooler than Merm Green.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 14). Deep Green is a little darker, more saturated, cooler than Merm Green.
The same difference applies the other way round: Merm Green is a little lighter, more muted, 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 Merm Green on the colour wheel See Deep Green on the colour wheel
All matches: Merm Green equivalents · Deep Green equivalents