Canary Green vs Goblin Green

How close are they?

ΔE 22.7, loose: different enough that you should pick on purpose. Goblin Green is noticeably darker, cooler than Canary Green.

Can I use Goblin Green instead of Canary Green?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 23). Goblin Green is noticeably darker, cooler than Canary Green.

Can I use Canary Green instead of Goblin Green?

The same difference applies the other way round: Canary Green is noticeably lighter, 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.