Basic Flesh vs Tyrant Skull

How close are they?

ΔE 8.8, close: similar, with a visible difference side by side. Tyrant Skull is a little darker, cooler than Basic Flesh.

Can I use Tyrant Skull instead of Basic Flesh?

Usually, if you are not matching paint already on the model. Close match (ΔE 9). Tyrant Skull is a little darker, cooler than Basic Flesh.

Can I use Basic Flesh instead of Tyrant Skull?

The same difference applies the other way round: Basic Flesh is a little lighter, 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.