British Green vs Park Green Flat

How close are they?

ΔE 8.1, close: similar, with a visible difference side by side. Park Green Flat is a little lighter, more muted, cooler than British Green.

Can I use Park Green Flat instead of British Green?

Usually, if you are not matching paint already on the model. Close match (ΔE 8). Park Green Flat is a little lighter, more muted, cooler than British Green.

Can I use British Green instead of Park Green Flat?

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