ΔE 11.5, fair: the same colour family, but not a straight swap. Reptilian Green is a little lighter, more saturated, cooler than Lupercal Green.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 12). Reptilian Green is a little lighter, more saturated, cooler than Lupercal Green.
The same difference applies the other way round: Lupercal Green is a little darker, 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 Lupercal Green on the colour wheel See Reptilian Green on the colour wheel
All matches: Lupercal Green equivalents · Reptilian Green equivalents