ΔE 11.3, fair: the same colour family, but not a straight swap. Coelia Greenshade is noticeably darker, warmer than Blue-Green. They are different kinds of paint: AK Interactive Blue-Green is an opaque base/layer paint and Citadel Coelia Greenshade is a wash/shade, 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). Coelia Greenshade is noticeably darker, warmer than Blue-Green. They are different kinds of paint.
The same difference applies the other way round: Blue-Green is noticeably lighter, 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 Blue-Green on the colour wheel See Coelia Greenshade on the colour wheel
All matches: Blue-Green equivalents · Coelia Greenshade equivalents