ochre vs yellow ocher

ochre and yellow ocher both are nouns.

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

As nouns, yellow ocher is a hyponym of ochre; that is, yellow ocher is a word with a more specific, narrower meaning than ochre:

ochre: any of various earths containing silica and alumina and ferric oxide; used as a pigment
yellow ocher: pigment consisting of a limonite mixed with clay and silica

Other hyponyms of ochre include sinoper, sinopia, sinopis, yellow ochre.

ochre (noun)	yellow ocher (noun)
a moderate yellow-orange to orange color	pigment consisting of a limonite mixed with clay and silica
any of various earths containing silica and alumina and ferric oxide; used as a pigment

ochre (adjective)	yellow ocher (adjective)
of a moderate orange-yellow color