ΔE 6.0, very close: most people won’t see a difference side by side. Moon Yellow is a little darker than Pearl Yellow. They are different kinds of paint: Tamiya Pearl Yellow is a pearl paint and Vallejo Moon Yellow is an opaque base/layer paint, so they won’t behave the same on the model even where the colour is close.
Yes, for most jobs. Very close match (ΔE 6). Moon Yellow is a little darker than Pearl Yellow. They are different kinds of paint.
The same difference applies the other way round: Pearl Yellow is a little lighter.
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.
See Pearl Yellow on the colour wheel See Moon Yellow on the colour wheel
All matches: Pearl Yellow equivalents · Moon Yellow equivalents