ΔE 14.1, fair: the same colour family, but not a straight swap. Fluor Violet is noticeably darker, more saturated than Dechala Lilac. They are different kinds of paint: Citadel Dechala Lilac is an opaque base/layer paint and Green Stuff World Fluor Violet is a fluorescent or effect paint, so they won’t behave the same on the model even where the colour is close.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 14). Fluor Violet is noticeably darker, more saturated than Dechala Lilac. They are different kinds of paint.
The same difference applies the other way round: Dechala Lilac is noticeably 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.
See Dechala Lilac on the colour wheel See Fluor Violet on the colour wheel
All matches: Dechala Lilac equivalents · Fluor Violet equivalents