Nazdreg Yellow vs Seraphim Flesh

How close are they?

ΔE 48.0, loose: different enough that you should pick on purpose. Seraphim Flesh is noticeably darker, much more muted than Nazdreg Yellow.

Can I use Seraphim Flesh instead of Nazdreg Yellow?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 48). Seraphim Flesh is noticeably darker, much more muted than Nazdreg Yellow.

Can I use Nazdreg Yellow instead of Seraphim Flesh?

The same difference applies the other way round: Nazdreg Yellow is noticeably 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.