Greenskin vs Sick Green

How close are they?

ΔE 22.8, loose: different enough that you should pick on purpose. Sick Green is noticeably lighter, much more saturated, warmer than Greenskin.

Can I use Sick Green instead of Greenskin?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 23). Sick Green is noticeably lighter, much more saturated, warmer than Greenskin.

Can I use Greenskin instead of Sick Green?

The same difference applies the other way round: Greenskin is noticeably darker, 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.