ΔE 19.4, loose: different enough that you should pick on purpose. Purple Black is a little darker, more muted than Iron Wolf.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 19). Purple Black is a little darker, more muted than Iron Wolf.
The same difference applies the other way round: Iron Wolf is a little lighter, more saturated.
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.
See Iron Wolf on the colour wheel See Purple Black on the colour wheel
All matches: Iron Wolf equivalents · Purple Black equivalents