Baal Crimson vs Devil Red

How close are they?

ΔE 30.2, loose: different enough that you should pick on purpose. Devil Red is a little lighter, cooler than Baal Crimson.

Can I use Devil Red instead of Baal Crimson?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 30). Devil Red is a little lighter, cooler than Baal Crimson.

Can I use Baal Crimson instead of Devil Red?

The same difference applies the other way round: Baal Crimson is a little 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.