ΔE 17.9, loose: different enough that you should pick on purpose. Light Green RLM25 is noticeably lighter, cooler than Forest Green.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 18). Light Green RLM25 is noticeably lighter, cooler than Forest Green.
The same difference applies the other way round: Forest Green is noticeably darker, 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 Forest Green on the colour wheel See Light Green RLM25 on the colour wheel
All matches: Forest Green equivalents · Light Green RLM25 equivalents