Purple vs Warpfiend Grey

How close are they?

ΔE 15.5, loose: different enough that you should pick on purpose. Warpfiend Grey is a little darker, much more muted, cooler than Purple.

Can I use Warpfiend Grey instead of Purple?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 15). Warpfiend Grey is a little darker, much more muted, cooler than Purple.

Can I use Purple instead of Warpfiend Grey?

The same difference applies the other way round: Purple 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.