Bright Ivory vs White Flesh

How close are they?

ΔE 8.9, close: similar, with a visible difference side by side. White Flesh is a little darker, warmer than Bright Ivory.

Can I use White Flesh instead of Bright Ivory?

Usually, if you are not matching paint already on the model. Close match (ΔE 9). White Flesh is a little darker, warmer than Bright Ivory.

Can I use Bright Ivory instead of White Flesh?

The same difference applies the other way round: Bright Ivory is a little lighter, cooler.

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.