ΔE 9.8, close: similar, with a visible difference side by side. Bright Sapphire is more saturated than Matt Sky Blue. They are different kinds of paint: AMMO by Mig Matt Sky Blue is an ink, glaze or transparent paint and Army Painter Bright Sapphire is an opaque base/layer paint, so they won’t behave the same on the model even where the colour is close.
Usually, if you are not matching paint already on the model. Close match (ΔE 10). Bright Sapphire is more saturated than Matt Sky Blue. They are different kinds of paint.
The same difference applies the other way round: Matt Sky Blue is more muted.
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 Matt Sky Blue on the colour wheel See Bright Sapphire on the colour wheel
All matches: Matt Sky Blue equivalents · Bright Sapphire equivalents