Light Feldgrau vs Pale Olive

How close are they?

ΔE 9.1, close: similar, with a visible difference side by side. Pale Olive is a little lighter, warmer than Light Feldgrau.

Can I use Pale Olive instead of Light Feldgrau?

Usually, if you are not matching paint already on the model. Close match (ΔE 9). Pale Olive is a little lighter, warmer than Light Feldgrau.

Can I use Light Feldgrau instead of Pale Olive?

The same difference applies the other way round: Light Feldgrau is a little darker, 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.