ΔE 17.6, loose: different enough that you should pick on purpose. Dechala Lilac is noticeably lighter, warmer than Matt Purple. They are different kinds of paint: AMMO by Mig Matt Purple is an ink, glaze or transparent paint and Citadel Dechala Lilac is an opaque base/layer paint, so they won’t behave the same on the model even where the colour is close.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 18). Dechala Lilac is noticeably lighter, warmer than Matt Purple. They are different kinds of paint.
The same difference applies the other way round: Matt Purple is noticeably darker, cooler.
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 Matt Purple on the colour wheel See Dechala Lilac on the colour wheel
All matches: Matt Purple equivalents · Dechala Lilac equivalents