Flat Green vs Light Green RLM25

How close are they?

ΔE 9.8, close: similar, with a visible difference side by side. Light Green RLM25 is a little darker, cooler than Flat Green.

Can I use Light Green RLM25 instead of Flat Green?

Usually, if you are not matching paint already on the model. Close match (ΔE 10). Light Green RLM25 is a little darker, cooler than Flat Green.

Can I use Flat Green instead of Light Green RLM25?

The same difference applies the other way round: Flat Green is a little lighter, 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.