Blood Angels Red vs Red Opulence

How close are they?

ΔE 6.3, close: similar, with a visible difference side by side. Red Opulence is a little lighter than Blood Angels Red.

Can I use Red Opulence instead of Blood Angels Red?

Usually, if you are not matching paint already on the model. Close match (ΔE 6). Red Opulence is a little lighter than Blood Angels Red.

Can I use Blood Angels Red instead of Red Opulence?

The same difference applies the other way round: Blood Angels Red is a little darker.

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.