ΔE 12.0, fair: the same colour family, but not a straight swap. Kislev Flesh is more saturated than Bison-Beast.
Can I use Kislev Flesh instead of Bison-Beast?
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 12). Kislev Flesh is more saturated than Bison-Beast.
Can I use Bison-Beast instead of Kislev Flesh?
The same difference applies the other way round: Bison-Beast is more muted.
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.