Overlord Olive vs Grey Brown

How close are they?

ΔE 9.0, close: similar, with a visible difference side by side. Grey Brown is a little lighter, more saturated than Overlord Olive.

Can I use Grey Brown instead of Overlord Olive?

Usually, if you are not matching paint already on the model. Close match (ΔE 9). Grey Brown is a little lighter, more saturated than Overlord Olive.

Can I use Overlord Olive instead of Grey Brown?

The same difference applies the other way round: Overlord Olive is a little darker, 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.