Solar Sand vs Arcane Gold

How close are they?

ΔE 16.3, loose: different enough that you should pick on purpose. Arcane Gold is much more muted, cooler than Solar Sand.

Can I use Arcane Gold instead of Solar Sand?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 16). Arcane Gold is much more muted, cooler than Solar Sand.

Can I use Solar Sand instead of Arcane Gold?

The same difference applies the other way round: Solar Sand is much more saturated, warmer.

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.