Feral Green vs Elixir Green

How close are they?

ΔE 18.8, loose: different enough that you should pick on purpose. Elixir Green is noticeably lighter, more muted, cooler than Feral Green.

Can I use Elixir Green instead of Feral Green?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 19). Elixir Green is noticeably lighter, more muted, cooler than Feral Green.

Can I use Feral Green instead of Elixir Green?

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