Arcane Blue vs Jade Green

How close are they?

ΔE 24.7, loose: different enough that you should pick on purpose. Jade Green is noticeably darker, much more saturated, warmer than Arcane Blue.

Can I use Jade Green instead of Arcane Blue?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 25). Jade Green is noticeably darker, much more saturated, warmer than Arcane Blue.

Can I use Arcane Blue instead of Jade Green?

The same difference applies the other way round: Arcane Blue is noticeably lighter, 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.