Burnt Turf vs Mustard Yellow

How close are they?

ΔE 18.5, loose: different enough that you should pick on purpose. Mustard Yellow is noticeably darker, more saturated than Burnt Turf.

Can I use Mustard Yellow instead of Burnt Turf?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 18). Mustard Yellow is noticeably darker, more saturated than Burnt Turf.

Can I use Burnt Turf instead of Mustard Yellow?

The same difference applies the other way round: Burnt Turf is noticeably lighter, 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.