Light Feldgrau vs Cement Grey

How close are they?

ΔE 8.2, close: similar, with a visible difference side by side. Cement Grey is more muted, warmer than Light Feldgrau.

Can I use Cement Grey instead of Light Feldgrau?

Usually, if you are not matching paint already on the model. Close match (ΔE 8). Cement Grey is more muted, warmer than Light Feldgrau.

Can I use Light Feldgrau instead of Cement Grey?

The same difference applies the other way round: Light Feldgrau is more saturated, 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.