Eternal Hunt 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 Eternal Hunt.

Can I use Slimer Green instead of Eternal Hunt?

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

Can I use Eternal Hunt instead of Slimer Green?

The same difference applies the other way round: Eternal Hunt 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.