ΔE 32.6, loose: different enough that you should pick on purpose. Sandy Yellow is a little darker, much more muted, warmer than Maize Yellow. They are different kinds of paint: Army Painter Maize Yellow is a one-coat contrast-style paint and Reaper Sandy Yellow is an opaque base/layer paint, so they won’t behave the same on the model even where the colour is close.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 33). Sandy Yellow is a little darker, much more muted, warmer than Maize Yellow. They are different kinds of paint.
The same difference applies the other way round: Maize Yellow is a little lighter, much 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.
See Maize Yellow on the colour wheel See Sandy Yellow on the colour wheel
All matches: Maize Yellow equivalents · Sandy Yellow equivalents