Sulfur Ore vs Imperial Gold

How close are they?

ΔE 9.8, close: similar, with a visible difference side by side. Imperial Gold is a little darker, more muted than Sulfur Ore.

Can I use Imperial Gold instead of Sulfur Ore?

Usually, if you are not matching paint already on the model. Close match (ΔE 10). Imperial Gold is a little darker, more muted than Sulfur Ore.

Can I use Sulfur Ore instead of Imperial Gold?

The same difference applies the other way round: Sulfur Ore 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.