Goblin Green vs Slimer Green

How close are they?

ΔE 20.9, loose: different enough that you should pick on purpose. Slimer Green is much more muted, warmer than Goblin Green.

Can I use Slimer Green instead of Goblin Green?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 21). Slimer Green is much more muted, warmer than Goblin Green.

Can I use Goblin Green instead of Slimer Green?

The same difference applies the other way round: Goblin Green is much more saturated, 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.