New Gold vs Arcane Gold

How close are they?

ΔE 7.5, close: similar, with a visible difference side by side. Arcane Gold is a little darker, warmer than New Gold.

Can I use Arcane Gold instead of New Gold?

Usually, if you are not matching paint already on the model. Close match (ΔE 7). Arcane Gold is a little darker, warmer than New Gold.

Can I use New Gold instead of Arcane Gold?

The same difference applies the other way round: New Gold is a little lighter, 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.