ΔE 7.4, close: similar, with a visible difference side by side. Leaf Green is a little darker, warmer than Aeldari Emerald. They are different kinds of paint: Citadel Aeldari Emerald is a one-coat contrast-style paint and Reaper Leaf Green is an opaque base/layer 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). Leaf Green is a little darker, warmer than Aeldari Emerald. They are different kinds of paint.
The same difference applies the other way round: Aeldari Emerald is a little lighter, cooler.
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 Aeldari Emerald on the colour wheel See Leaf Green on the colour wheel
All matches: Aeldari Emerald equivalents · Leaf Green equivalents