Fulgurite Copper vs Caesar Red

How close are they?

ΔE 28.8, loose: different enough that you should pick on purpose. Caesar Red is a little lighter, more muted, cooler than Fulgurite Copper.

Can I use Caesar Red instead of Fulgurite Copper?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 29). Caesar Red is a little lighter, more muted, cooler than Fulgurite Copper.

Can I use Fulgurite Copper instead of Caesar Red?

The same difference applies the other way round: Fulgurite Copper is a little darker, more saturated, 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.