ΔE 13.9, fair: the same colour family, but not a straight swap. Pale Green is more saturated, warmer than Flat Green.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 14). Pale Green is more saturated, warmer than Flat Green.
The same difference applies the other way round: Flat Green is 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 Flat Green on the colour wheel See Pale Green on the colour wheel
All matches: Flat Green equivalents · Pale Green equivalents