ΔE 7.7, close: similar, with a visible difference side by side. Creed Camo is a little lighter, cooler than Rock Grey. They are different kinds of paint: AMMO by Mig Rock Grey is an opaque base/layer paint and Citadel Creed Camo is a one-coat contrast-style 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 8). Creed Camo is a little lighter, cooler than Rock Grey. They are different kinds of paint.
The same difference applies the other way round: Rock Grey is a little darker, 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 Rock Grey on the colour wheel See Creed Camo on the colour wheel
All matches: Rock Grey equivalents · Creed Camo equivalents