Sunburned Skin vs Flayed One Flesh

How close are they?

ΔE 16.6, loose: different enough that you should pick on purpose. Flayed One Flesh is a little darker, much more muted than Sunburned Skin.

Can I use Flayed One Flesh instead of Sunburned Skin?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 17). Flayed One Flesh is a little darker, much more muted than Sunburned Skin.

Can I use Sunburned Skin instead of Flayed One Flesh?

The same difference applies the other way round: Sunburned Skin is a little lighter, much 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.