ΔE 11.2, fair: the same colour family, but not a straight swap. Light Green RLM25 is more saturated, cooler than Field Gray.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 11). Light Green RLM25 is more saturated, cooler than Field Gray.
The same difference applies the other way round: Field Gray is 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 Field Gray on the colour wheel See Light Green RLM25 on the colour wheel
All matches: Field Gray equivalents · Light Green RLM25 equivalents