ΔE 12.8, fair: the same colour family, but not a straight swap. Faded Green is noticeably lighter, more saturated, warmer than Light Feldgrau.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 13). Faded Green is noticeably lighter, more saturated, warmer than Light Feldgrau.
The same difference applies the other way round: Light Feldgrau is noticeably darker, 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 Light Feldgrau on the colour wheel See Faded Green on the colour wheel
All matches: Light Feldgrau equivalents · Faded Green equivalents