Plague Yellow vs Desert Yellow

How close are they?

ΔE 7.0, close: similar, with a visible difference side by side. Desert Yellow is more saturated than Plague Yellow.

Can I use Desert Yellow instead of Plague Yellow?

Usually, if you are not matching paint already on the model. Close match (ΔE 7). Desert Yellow is more saturated than Plague Yellow.

Can I use Plague Yellow instead of Desert Yellow?

The same difference applies the other way round: Plague Yellow is more muted.

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.