Potion Green vs Nuclear Sludge

How close are they?

ΔE 9.8, close: similar, with a visible difference side by side. Nuclear Sludge is a little lighter, more saturated, warmer than Potion Green.

Can I use Nuclear Sludge instead of Potion Green?

Usually, if you are not matching paint already on the model. Close match (ΔE 10). Nuclear Sludge is a little lighter, more saturated, warmer than Potion Green.

Can I use Potion Green instead of Nuclear Sludge?

The same difference applies the other way round: Potion Green is a little darker, more muted, 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.