Blighted Gold vs Arcane Gold

How close are they?

ΔE 36.8, loose: different enough that you should pick on purpose. Arcane Gold is more muted, warmer than Blighted Gold.

Can I use Arcane Gold instead of Blighted Gold?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 37). Arcane Gold is more muted, warmer than Blighted Gold.

Can I use Blighted Gold instead of Arcane Gold?

The same difference applies the other way round: Blighted Gold is more saturated, 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.