The Red Baron vs Astorath Red

How close are they?

ΔE 20.2, loose: different enough that you should pick on purpose. Astorath Red is a little darker, much more muted than The Red Baron.

Can I use Astorath Red instead of The Red Baron?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 20). Astorath Red is a little darker, much more muted than The Red Baron.

Can I use The Red Baron instead of Astorath Red?

The same difference applies the other way round: The Red Baron is a little lighter, much more saturated.

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.