Demon Red vs Sanctuary Red

How close are they?

ΔE 8.4, close: similar, with a visible difference side by side. Sanctuary Red is a little lighter, more saturated than Demon Red.

Can I use Sanctuary Red instead of Demon Red?

Usually, if you are not matching paint already on the model. Close match (ΔE 8). Sanctuary Red is a little lighter, more saturated than Demon Red.

Can I use Demon Red instead of Sanctuary Red?

The same difference applies the other way round: Demon Red is a little darker, more muted.

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.