ΔE 11.0, fair: the same colour family, but not a straight swap. Shadow Violet is a little darker, more muted than Druchii Violet. They are different kinds of paint: Citadel Druchii Violet is a wash/shade and Reaper Shadow Violet is an opaque base/layer 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 11). Shadow Violet is a little darker, more muted than Druchii Violet. They are different kinds of paint.
The same difference applies the other way round: Druchii Violet 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 Druchii Violet on the colour wheel See Shadow Violet on the colour wheel
All matches: Druchii Violet equivalents · Shadow Violet equivalents