ΔE 9.0, close: similar, with a visible difference side by side. Ultramarine Blue is cooler than Braineater Azure.
Usually, if you are not matching paint already on the model. Close match (ΔE 9). Ultramarine Blue is cooler than Braineater Azure.
The same difference applies the other way round: Braineater Azure is 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 Braineater Azure on the colour wheel See Ultramarine Blue on the colour wheel
All matches: Braineater Azure equivalents · Ultramarine Blue equivalents