ΔE 12.9, fair: the same colour family, but not a straight swap. Flayed One Flesh is a little darker, more muted, warmer than Portland Stone No.64.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 13). Flayed One Flesh is a little darker, more muted, warmer than Portland Stone No.64.
The same difference applies the other way round: Portland Stone No.64 is a little lighter, more saturated, cooler.
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 Portland Stone No.64 on the colour wheel See Flayed One Flesh on the colour wheel
All matches: Portland Stone No.64 equivalents · Flayed One Flesh equivalents