Khorne Red vs Purple

How close are they?

ΔE 21.3, loose: different enough that you should pick on purpose. Purple is noticeably lighter, more saturated, cooler than Khorne Red.

Can I use Purple instead of Khorne Red?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 21). Purple is noticeably lighter, more saturated, cooler than Khorne Red.

Can I use Khorne Red instead of Purple?

The same difference applies the other way round: Khorne Red is noticeably darker, 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.