Magenta vs Kakophoni Purple

How close are they?

ΔE 33.0, loose: different enough that you should pick on purpose. Kakophoni Purple is a little darker, much more muted, cooler than Magenta.

Can I use Kakophoni Purple instead of Magenta?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 33). Kakophoni Purple is a little darker, much more muted, cooler than Magenta.

Can I use Magenta instead of Kakophoni Purple?

The same difference applies the other way round: Magenta is a little lighter, much more saturated, 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.