Chaotic Red vs Purple Shadow

How close are they?

ΔE 9.2, close: similar, with a visible difference side by side. Purple Shadow is more saturated, cooler than Chaotic Red.

Can I use Purple Shadow instead of Chaotic Red?

Usually, if you are not matching paint already on the model. Close match (ΔE 9). Purple Shadow is more saturated, cooler than Chaotic Red.

Can I use Chaotic Red instead of Purple Shadow?

The same difference applies the other way round: Chaotic Red is more muted, 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.