Orange Brown vs Martian Ironearth

How close are they?

ΔE 7.1, close: similar, with a visible difference side by side. Martian Ironearth is a little darker, more muted than Orange Brown. They are different kinds of paint: AK Interactive Orange Brown is an opaque base/layer paint and Citadel Martian Ironearth is a technical paint or medium, so they won’t behave the same on the model even where the colour is close.

Can I use Martian Ironearth instead of Orange Brown?

Usually, if you are not matching paint already on the model. Close match (ΔE 7). Martian Ironearth is a little darker, more muted than Orange Brown. They are different kinds of paint.

Can I use Orange Brown instead of Martian Ironearth?

The same difference applies the other way round: Orange Brown is a little lighter, more saturated.

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.