Wyrmling Red vs Blood Red

How close are they?

ΔE 16.4, loose: different enough that you should pick on purpose. Blood Red is noticeably darker, warmer than Wyrmling Red.

Can I use Blood Red instead of Wyrmling Red?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 16). Blood Red is noticeably darker, warmer than Wyrmling Red.

Can I use Wyrmling Red instead of Blood Red?

The same difference applies the other way round: Wyrmling Red is noticeably lighter, 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.