ΔE 10.8, fair: the same colour family, but not a straight swap. Ghost Green is a little darker, warmer than Light Phthalo Green.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 11). Ghost Green is a little darker, warmer than Light Phthalo Green.
The same difference applies the other way round: Light Phthalo Green is a little lighter, 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 Light Phthalo Green on the colour wheel See Ghost Green on the colour wheel
All matches: Light Phthalo Green equivalents · Ghost Green equivalents