Blue Black vs Thunder Storm

How close are they?

ΔE 5.7, very close: most people won’t see a difference side by side. Thunder Storm is a little darker, cooler than Blue Black.

Can I use Thunder Storm instead of Blue Black?

Yes, for most jobs. Very close match (ΔE 6). Thunder Storm is a little darker, cooler than Blue Black.

Can I use Blue Black instead of Thunder Storm?

The same difference applies the other way round: Blue Black is a little lighter, 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.