ΔE 5.9, very close: most people won’t see a difference side by side. Astrogranite is a little darker than Dark Ghost Gray. They are different kinds of paint: AMMO by Mig Dark Ghost Gray is an opaque base/layer paint and Citadel Astrogranite is a technical paint or medium, so they won’t behave the same on the model even where the colour is close.
Yes, for most jobs. Very close match (ΔE 6). Astrogranite is a little darker than Dark Ghost Gray. They are different kinds of paint.
The same difference applies the other way round: Dark Ghost Gray is a little 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 Dark Ghost Gray on the colour wheel See Astrogranite on the colour wheel
All matches: Dark Ghost Gray equivalents · Astrogranite equivalents