ΔE 6.7, close: similar, with a visible difference side by side. Yellow is more saturated than Bad Moon Yellow. They are different kinds of paint: Citadel Bad Moon Yellow is a one-coat contrast-style paint and Green Stuff World Yellow is an ink, glaze or transparent paint, so they won’t behave the same on the model even where the colour is close.
Usually, if you are not matching paint already on the model. Close match (ΔE 7). Yellow is more saturated than Bad Moon Yellow. They are different kinds of paint.
The same difference applies the other way round: Bad Moon 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.
See Bad Moon Yellow on the colour wheel See Yellow on the colour wheel
All matches: Bad Moon Yellow equivalents · Yellow equivalents