Angron Red Clear vs Sanguinem Red

How close are they?

ΔE 15.8, loose: different enough that you should pick on purpose. Sanguinem Red is noticeably lighter, more muted than Angron Red Clear. They are different kinds of paint: Citadel Angron Red Clear is an opaque base/layer paint and Green Stuff World Sanguinem Red is an ink, glaze or transparent paint, so they won’t behave the same on the model even where the colour is close.

Can I use Sanguinem Red instead of Angron Red Clear?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 16). Sanguinem Red is noticeably lighter, more muted than Angron Red Clear. They are different kinds of paint.

Can I use Angron Red Clear instead of Sanguinem Red?

The same difference applies the other way round: Angron Red Clear is noticeably darker, more saturated.

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.