Coal Black vs Emerald

How close are they?

ΔE 21.1, loose: different enough that you should pick on purpose. Emerald is a little lighter, more saturated, warmer than Coal Black.

Can I use Emerald instead of Coal Black?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 21). Emerald is a little lighter, more saturated, warmer than Coal Black.

Can I use Coal Black instead of Emerald?

The same difference applies the other way round: Coal Black is a little darker, more muted, 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.