Vampire Red vs Eye of Terror

How close are they?

ΔE 9.9, close: similar, with a visible difference side by side. Eye of Terror is a little darker, cooler than Vampire Red.

Can I use Eye of Terror instead of Vampire Red?

Usually, if you are not matching paint already on the model. Close match (ΔE 10). Eye of Terror is a little darker, cooler than Vampire Red.

Can I use Vampire Red instead of Eye of Terror?

The same difference applies the other way round: Vampire Red 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.