Impish Rouge vs Warlock Purple

How close are they?

ΔE 15.3, loose: different enough that you should pick on purpose. Warlock Purple is a little darker, more saturated than Impish Rouge.

Can I use Warlock Purple instead of Impish Rouge?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 15). Warlock Purple is a little darker, more saturated than Impish Rouge.

Can I use Impish Rouge instead of Warlock Purple?

The same difference applies the other way round: Impish Rouge is a little lighter, 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.