Aqua Alchemy vs Sotek Green

How close are they?

ΔE 21.1, loose: different enough that you should pick on purpose. Sotek Green is noticeably darker, more muted, cooler than Aqua Alchemy.

Can I use Sotek Green instead of Aqua Alchemy?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 21). Sotek Green is noticeably darker, more muted, cooler than Aqua Alchemy.

Can I use Aqua Alchemy instead of Sotek Green?

The same difference applies the other way round: Aqua Alchemy is noticeably lighter, 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.