Greenskin vs Eldritch

How close are they?

ΔE 22.8, loose: different enough that you should pick on purpose. Eldritch is a little lighter, much more muted, cooler than Greenskin.

Can I use Eldritch instead of Greenskin?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 23). Eldritch is a little lighter, much more muted, cooler than Greenskin.

Can I use Greenskin instead of Eldritch?

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