Copper Fire vs Forged Red

How close are they?

ΔE 6.6, close: similar, with a visible difference side by side. Forged Red is a little darker than Copper Fire.

Can I use Forged Red instead of Copper Fire?

Usually, if you are not matching paint already on the model. Close match (ΔE 7). Forged Red is a little darker than Copper Fire.

Can I use Copper Fire instead of Forged Red?

The same difference applies the other way round: Copper Fire is a little lighter.

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.