ΔE 6.6, close: similar, with a visible difference side by side. Fluor Green is a little darker than Ferocious Green. They are different kinds of paint: Army Painter Ferocious Green is an opaque base/layer paint and Green Stuff World Fluor Green is an ink, glaze or transparent paint, so they won’t behave the same on the model even where the colour is close.
Usually, if you are not matching paint already on the model. Close match (ΔE 7). Fluor Green is a little darker than Ferocious Green. They are different kinds of paint.
The same difference applies the other way round: Ferocious Green is a little lighter.
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 Fluor Green on the colour wheel
All matches: Ferocious Green equivalents · Fluor Green equivalents