Guardian Green vs Park Green Flat

How close are they?

ΔE 6.5, close: similar, with a visible difference side by side. Park Green Flat is more muted, cooler than Guardian Green.

Can I use Park Green Flat instead of Guardian Green?

Usually, if you are not matching paint already on the model. Close match (ΔE 6). Park Green Flat is more muted, cooler than Guardian Green.

Can I use Guardian Green instead of Park Green Flat?

The same difference applies the other way round: Guardian 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.