Olive-Brown Ops vs Cam. Middle Brown

How close are they?

ΔE 6.6, close: similar, with a visible difference side by side. Cam. Middle Brown is a little lighter than Olive-Brown Ops.

Can I use Cam. Middle Brown instead of Olive-Brown Ops?

Usually, if you are not matching paint already on the model. Close match (ΔE 7). Cam. Middle Brown is a little lighter than Olive-Brown Ops.

Can I use Olive-Brown Ops instead of Cam. Middle Brown?

The same difference applies the other way round: Olive-Brown Ops is a little darker.

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.