ΔE 8.0, close: similar, with a visible difference side by side. Medium Blue is a little lighter, more saturated, cooler than Ahriman Blue.
Usually, if you are not matching paint already on the model. Close match (ΔE 8). Medium Blue is a little lighter, more saturated, cooler than Ahriman Blue.
The same difference applies the other way round: Ahriman Blue is a little darker, more muted, 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 Ahriman Blue on the colour wheel See Medium Blue on the colour wheel
All matches: Ahriman Blue equivalents · Medium Blue equivalents