Helmet Brown vs Dark Yellow Green

How close are they?

ΔE 6.8, close: similar, with a visible difference side by side. Dark Yellow Green is more saturated than Helmet Brown.

Can I use Dark Yellow Green instead of Helmet Brown?

Usually, if you are not matching paint already on the model. Close match (ΔE 7). Dark Yellow Green is more saturated than Helmet Brown.

Can I use Helmet Brown instead of Dark Yellow Green?

The same difference applies the other way round: Helmet Brown is more muted.

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.