Bloodstone vs Red

How close are they?

ΔE 21.4, loose: different enough that you should pick on purpose. Red is more saturated, cooler than Bloodstone.

Can I use Red instead of Bloodstone?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 21). Red is more saturated, cooler than Bloodstone.

Can I use Bloodstone instead of Red?

The same difference applies the other way round: Bloodstone is more muted, 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.