ΔE 14.6, fair: the same colour family, but not a straight swap. Piggy Purple Ink is more saturated, warmer than Cloudburst Blue. They are different kinds of paint: Army Painter Cloudburst Blue is a one-coat contrast-style paint and Formula P3 Piggy Purple Ink is an ink, glaze or transparent 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 15). Piggy Purple Ink is more saturated, warmer than Cloudburst Blue. They are different kinds of paint.
The same difference applies the other way round: Cloudburst Blue is more muted, 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 Cloudburst Blue on the colour wheel See Piggy Purple Ink on the colour wheel
All matches: Cloudburst Blue equivalents · Piggy Purple Ink equivalents