Marigold Yellow vs Sand Yellow

How close are they?

ΔE 20.1, loose: different enough that you should pick on purpose. Sand Yellow is a little lighter, more muted, cooler than Marigold Yellow.

Can I use Sand Yellow instead of Marigold Yellow?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 20). Sand Yellow is a little lighter, more muted, cooler than Marigold Yellow.

Can I use Marigold Yellow instead of Sand Yellow?

The same difference applies the other way round: Marigold Yellow is a little darker, more saturated, warmer.

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.