Pure Green vs Gauss Green

How close are they?

ΔE 18.5, loose: different enough that you should pick on purpose. Gauss Green is more muted, cooler than Pure Green.

Can I use Gauss Green instead of Pure Green?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 18). Gauss Green is more muted, cooler than Pure Green.

Can I use Pure Green instead of Gauss Green?

The same difference applies the other way round: Pure Green is more saturated, warmer.

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.