Screamer Pink vs Volcano Brown

How close are they?

ΔE 15.4, loose: different enough that you should pick on purpose. Volcano Brown is a little lighter, much more muted than Screamer Pink.

Can I use Volcano Brown instead of Screamer Pink?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 15). Volcano Brown is a little lighter, much more muted than Screamer Pink.

Can I use Screamer Pink instead of Volcano Brown?

The same difference applies the other way round: Screamer Pink is a little darker, 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.