Iron Warriors vs Doom Metal

How close are they?

ΔE 9.6, close: similar, with a visible difference side by side. Doom Metal is a little lighter than Iron Warriors.

Can I use Doom Metal instead of Iron Warriors?

Usually, if you are not matching paint already on the model. Close match (ΔE 10). Doom Metal is a little lighter than Iron Warriors.

Can I use Iron Warriors instead of Doom Metal?

The same difference applies the other way round: Iron Warriors 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.