Mephiston Red vs Blood Red

How close are they?

ΔE 7.1, close: similar, with a visible difference side by side. Blood Red is a little lighter, more saturated than Mephiston Red.

Can I use Blood Red instead of Mephiston Red?

Usually, if you are not matching paint already on the model. Close match (ΔE 7). Blood Red is a little lighter, more saturated than Mephiston Red.

Can I use Mephiston Red instead of Blood Red?

The same difference applies the other way round: Mephiston 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.