ΔE 6.5, close: similar, with a visible difference side by side. Yellow Ochre is a little darker than Mustard.
Usually, if you are not matching paint already on the model. Close match (ΔE 7). Yellow Ochre is a little darker than Mustard.
The same difference applies the other way round: Mustard 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 Mustard on the colour wheel See Yellow Ochre on the colour wheel
All matches: Mustard equivalents · Yellow Ochre equivalents