ΔE 12.4, fair: the same colour family, but not a straight swap. Dark Angels Green is a little lighter, more saturated, cooler than Russian Green 4BO. They are different kinds of paint: AK Interactive Russian Green 4BO is an opaque base/layer paint and Citadel Dark Angels Green is a one-coat contrast-style paint, so they won’t behave the same on the model even where the colour is close.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 12). Dark Angels Green is a little lighter, more saturated, cooler than Russian Green 4BO. They are different kinds of paint.
The same difference applies the other way round: Russian Green 4BO is a little darker, 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 Russian Green 4BO on the colour wheel See Dark Angels Green on the colour wheel
All matches: Russian Green 4BO equivalents · Dark Angels Green equivalents