ΔE 7.6, close: similar, with a visible difference side by side. Forest Green is a little darker, more saturated, warmer than Lupercal Green.
Usually, if you are not matching paint already on the model. Close match (ΔE 8). Forest Green is a little darker, more saturated, warmer than Lupercal Green.
The same difference applies the other way round: Lupercal Green is a little lighter, more muted, 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 Lupercal Green on the colour wheel See Forest Green on the colour wheel
All matches: Lupercal Green equivalents · Forest Green equivalents