Dwarven Flesh vs Medium Flesh

How close are they?

ΔE 7.7, close: similar, with a visible difference side by side. Medium Flesh is more muted than Dwarven Flesh.

Can I use Medium Flesh instead of Dwarven Flesh?

Usually, if you are not matching paint already on the model. Close match (ΔE 8). Medium Flesh is more muted than Dwarven Flesh.

Can I use Dwarven Flesh instead of Medium Flesh?

The same difference applies the other way round: Dwarven Flesh is 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.