Skorne Red vs Crimson

How close are they?

ΔE 33.7, loose: different enough that you should pick on purpose. Crimson is noticeably lighter, cooler than Skorne Red.

Can I use Crimson instead of Skorne Red?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 34). Crimson is noticeably lighter, cooler than Skorne Red.

Can I use Skorne Red instead of Crimson?

The same difference applies the other way round: Skorne Red is noticeably darker, 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.