ΔE 11.3, fair: the same colour family, but not a straight swap. Cobalt Teal is a little lighter, warmer than Raging Sea. They are different kinds of paint: Army Painter Raging Sea is a one-coat contrast-style paint and Golden Cobalt Teal 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). Cobalt Teal is a little lighter, warmer than Raging Sea. They are different kinds of paint.
The same difference applies the other way round: Raging Sea is a little darker, 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 Raging Sea on the colour wheel See Cobalt Teal on the colour wheel
All matches: Raging Sea equivalents · Cobalt Teal equivalents