ΔE 11.6, fair: the same colour family, but not a straight swap. Stratos Blue is noticeably darker than Marine Blue. They are different kinds of paint: AMMO by Mig Marine Blue is an ink, glaze or transparent paint and Army Painter Stratos Blue 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 12). Stratos Blue is noticeably darker than Marine Blue. They are different kinds of paint.
The same difference applies the other way round: Marine Blue is noticeably lighter.
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 Marine Blue on the colour wheel See Stratos Blue on the colour wheel
All matches: Marine Blue equivalents · Stratos Blue equivalents