Orc Blood vs Neo Pink

How close are they?

ΔE 15.7, loose: different enough that you should pick on purpose. Neo Pink is a little darker, more saturated, warmer than Orc Blood.

Can I use Neo Pink instead of Orc Blood?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 16). Neo Pink is a little darker, more saturated, warmer than Orc Blood.

Can I use Orc Blood instead of Neo Pink?

The same difference applies the other way round: Orc Blood is a little lighter, more muted, cooler.

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.