Bloodstone vs Dark Flesh Tone

How close are they?

ΔE 9.5, close: similar, with a visible difference side by side. Dark Flesh Tone is more muted, cooler than Bloodstone.

Can I use Dark Flesh Tone instead of Bloodstone?

Usually, if you are not matching paint already on the model. Close match (ΔE 9). Dark Flesh Tone is more muted, cooler than Bloodstone.

Can I use Bloodstone instead of Dark Flesh Tone?

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