ΔE 7.1, close: similar, with a visible difference side by side. Warp Lightning is a little darker, more muted than Fluorescent Green. They are different kinds of paint: AK Interactive Fluorescent Green is a fluorescent or effect paint and Citadel Warp Lightning is a one-coat contrast-style 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). Warp Lightning is a little darker, more muted than Fluorescent Green. They are different kinds of paint.
The same difference applies the other way round: Fluorescent Green is a little lighter, more saturated.
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 Fluorescent Green on the colour wheel See Warp Lightning on the colour wheel
All matches: Fluorescent Green equivalents · Warp Lightning equivalents