Barren Dune vs Yellow FS33531

How close are they?

ΔE 7.7, close: similar, with a visible difference side by side. Yellow FS33531 is more muted, warmer than Barren Dune.

Can I use Yellow FS33531 instead of Barren Dune?

Usually, if you are not matching paint already on the model. Close match (ΔE 8). Yellow FS33531 is more muted, warmer than Barren Dune.

Can I use Barren Dune instead of Yellow FS33531?

The same difference applies the other way round: Barren Dune is more saturated, 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.