Elysian Green vs Warcry Green

How close are they?

ΔE 22.7, loose: different enough that you should pick on purpose. Warcry Green is noticeably darker, more muted, cooler than Elysian Green.

Can I use Warcry Green instead of Elysian Green?

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

Can I use Elysian Green instead of Warcry Green?

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