Where does “ōchra” come from?

ōchra (Latin) comes from Ancient Greek ὤχρα, from Ancient Greek ὠχρός — pale, sallow, wan.

Ancestry of “ōchra”, step by step

Step	Language	Word	Meaning
1	Ancient Greek	ὤχρα	pale yellow; yellow ochre
2	Ancient Greek	ὠχρός	pale, sallow, wan