Gehenna's Gold vs Metallic Orange

How close are they?

ΔE 26.6, loose: different enough that you should pick on purpose. Metallic Orange is much more saturated, warmer than Gehenna's Gold.

Can I use Metallic Orange instead of Gehenna's Gold?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 27). Metallic Orange is much more saturated, warmer than Gehenna's Gold.

Can I use Gehenna's Gold instead of Metallic Orange?

The same difference applies the other way round: Gehenna's Gold is much more muted, cooler.

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.