ΔE 11.0, fair: the same colour family, but not a straight swap. Morghast Bone is a little darker, more muted, cooler than Matt Light Clay. They are different kinds of paint: AMMO by Mig Matt Light Clay is an ink, glaze or transparent paint and Citadel Morghast Bone is an opaque base/layer paint, so they won’t behave the same on the model even where the colour is close.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 11). Morghast Bone is a little darker, more muted, cooler than Matt Light Clay. They are different kinds of paint.
The same difference applies the other way round: Matt Light Clay is a little lighter, more saturated, 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 Matt Light Clay on the colour wheel See Morghast Bone on the colour wheel
All matches: Matt Light Clay equivalents · Morghast Bone equivalents