ΔE 14.8, fair: the same colour family, but not a straight swap. Russian Green 1 is noticeably darker, cooler than Ferocious Green.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 15). Russian Green 1 is noticeably darker, cooler than Ferocious Green.
The same difference applies the other way round: Ferocious Green is noticeably lighter, 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 Ferocious Green on the colour wheel See Russian Green 1 on the colour wheel
All matches: Ferocious Green equivalents · Russian Green 1 equivalents