Subordinate Ochre is a lower-ranked member of the Melnorme Trader vessel, Inevitably Successful in All Circumstances. He seems to be on friendly terms with Trademaster Greenish, as evidenced by Greenish's anecdote that he had predicted The Captain would visit them shortly, by saying "Fe-Fi-Fo-Fum! I smell the feet of a Hu-Hu-Man!", which was of great amusement to both of them. Perhaps coincidentally, The Captain did arrive later on that day. Ochre's exact job other than a subordinate to Greenish is not known, though one can presume it involves tending to the ship.
Given the reference that Greenish made in his rhyme to the fairy tale Jack and the Beanstalk, the similarity between Ochre and ogre can hardly be a coincidence.