Word Bearers Red vs Dull Red

How close are they?

ΔE 19.1, loose: different enough that you should pick on purpose. Dull Red is noticeably lighter, warmer than Word Bearers Red.

Can I use Dull Red instead of Word Bearers Red?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 19). Dull Red is noticeably lighter, warmer than Word Bearers Red.

Can I use Word Bearers Red instead of Dull Red?

The same difference applies the other way round: Word Bearers Red is noticeably darker, cooler.

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.