Screamer Pink vs Hastur Purple

How close are they?

ΔE 8.4, close: similar, with a visible difference side by side. Hastur Purple is more saturated than Screamer Pink.

Can I use Hastur Purple instead of Screamer Pink?

Usually, if you are not matching paint already on the model. Close match (ΔE 8). Hastur Purple is more saturated than Screamer Pink.

Can I use Screamer Pink instead of Hastur Purple?

The same difference applies the other way round: Screamer Pink is more muted.

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.