Murder Scene vs Deep Purple

How close are they?

ΔE 6.5, close: similar, with a visible difference side by side. Deep Purple is a little darker, cooler than Murder Scene.

Can I use Deep Purple instead of Murder Scene?

Usually, if you are not matching paint already on the model. Close match (ΔE 6). Deep Purple is a little darker, cooler than Murder Scene.

Can I use Murder Scene instead of Deep Purple?

The same difference applies the other way round: Murder Scene is a little lighter, 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.