Screamer Pink vs Black Red

How close are they?

ΔE 16.1, loose: different enough that you should pick on purpose. Black Red is a little darker, much more muted than Screamer Pink.

Can I use Black Red instead of Screamer Pink?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 16). Black Red is a little darker, much more muted than Screamer Pink.

Can I use Screamer Pink instead of Black Red?

The same difference applies the other way round: Screamer Pink is a little lighter, much more saturated.

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.