Medieval Forest vs Legion Green

How close are they?

ΔE 9.0, close: similar, with a visible difference side by side. Legion Green is a little darker, cooler than Medieval Forest.

Can I use Legion Green instead of Medieval Forest?

Usually, if you are not matching paint already on the model. Close match (ΔE 9). Legion Green is a little darker, cooler than Medieval Forest.

Can I use Medieval Forest instead of Legion Green?

The same difference applies the other way round: Medieval Forest 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.