ΔE 12.2, fair: the same colour family, but not a straight swap. Raging Sea is noticeably lighter, cooler than Turquoise. They are different kinds of paint: AMMO by Mig Turquoise is an opaque base/layer paint and Army Painter Raging Sea is a one-coat contrast-style 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 12). Raging Sea is noticeably lighter, cooler than Turquoise. They are different kinds of paint.
The same difference applies the other way round: Turquoise is noticeably darker, warmer.
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 Turquoise on the colour wheel See Raging Sea on the colour wheel
All matches: Turquoise equivalents · Raging Sea equivalents