ΔE 7.1, close: similar, with a visible difference side by side. Tyran Blue is warmer than Blue. They are different kinds of paint: AMMO by Mig Blue is an opaque base/layer paint and Citadel Tyran Blue is a wash/shade, 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 7). Tyran Blue is warmer than Blue. They are different kinds of paint.
The same difference applies the other way round: Blue is 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 Blue on the colour wheel See Tyran Blue on the colour wheel
All matches: Blue equivalents · Tyran Blue equivalents