yellow ocher vs yellow ochre

yellow ocher and yellow ochre both are nouns.

Word	Noun	Adjective	Verb	Adverb
yellow ocher	Yes	No	No	No
yellow ochre	Yes	No	No	No

As nouns, yellow ocher and yellow ochre are synonyms defined as:

yellow ocher and yellow ochre: pigment consisting of a limonite mixed with clay and silica

yellow ocher (noun)	yellow ochre (noun)
pigment consisting of a limonite mixed with clay and silica	pigment consisting of a limonite mixed with clay and silica