ΔE 10.3, fair: the same colour family, but not a straight swap. Corpse Pale is a little lighter, more muted than Matt Tanned Flesh. They are different kinds of paint: AMMO by Mig Matt Tanned Flesh is an ink, glaze or transparent paint and Army Painter Corpse Pale 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 10). Corpse Pale is a little lighter, more muted than Matt Tanned Flesh. They are different kinds of paint.
The same difference applies the other way round: Matt Tanned Flesh is a little darker, more saturated.
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 Tanned Flesh on the colour wheel See Corpse Pale on the colour wheel
All matches: Matt Tanned Flesh equivalents · Corpse Pale equivalents