Midnight Olive vs Swamp Green

How close are they?

ΔE 6.6, close: similar, with a visible difference side by side. Swamp Green is a little darker, warmer than Midnight Olive.

Can I use Swamp Green instead of Midnight Olive?

Usually, if you are not matching paint already on the model. Close match (ΔE 7). Swamp Green is a little darker, warmer than Midnight Olive.

Can I use Midnight Olive instead of Swamp Green?

The same difference applies the other way round: Midnight Olive 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.