ΔE 18.5, loose: different enough that you should pick on purpose. Chromium Oxide Green Dark is a little darker, more saturated, cooler than Prairie Ochre.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 18). Chromium Oxide Green Dark is a little darker, more saturated, cooler than Prairie Ochre.
The same difference applies the other way round: Prairie Ochre is a little lighter, more muted, 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.
See Prairie Ochre on the colour wheel See Chromium Oxide Green Dark on the colour wheel
All matches: Prairie Ochre equivalents · Chromium Oxide Green Dark equivalents