Crusader Skin vs Wild Beast

How close are they?

ΔE 17.9, loose: different enough that you should pick on purpose. Wild Beast is noticeably darker, more saturated than Crusader Skin.

Can I use Wild Beast instead of Crusader Skin?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 18). Wild Beast is noticeably darker, more saturated than Crusader Skin.

Can I use Crusader Skin instead of Wild Beast?

The same difference applies the other way round: Crusader Skin is noticeably lighter, more muted.

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.