Commando Green vs Green Yellow

How close are they?

ΔE 8.1, close: similar, with a visible difference side by side. Green Yellow is a little darker, warmer than Commando Green.

Can I use Green Yellow instead of Commando Green?

Usually, if you are not matching paint already on the model. Close match (ΔE 8). Green Yellow is a little darker, warmer than Commando Green.

Can I use Commando Green instead of Green Yellow?

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

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.