schemeyoudaoicibaDictYouDict[scheme 词源字典]
scheme: [16] Greek skhéma meant ‘form, figure’. Latin took it over as schēma and used it as the equivalent of figure in a range of applications, such as ‘figure of speech’ and ‘diagram’, many of which were originally taken over by English (‘In the text, by a very elegant scheme of speech he does … once more set them at liberty’, John Tillotson, Sermons 1684). The modern sense ‘plan’, which presumably developed out of ‘diagram’, began to emerge in the mid 17th century.
[scheme etymology, scheme origin, 英语词源]
scheme (n.)youdaoicibaDictYouDict
1550s, "figure of speech," from Medieval Latin schema "shape, figure, form, appearance; figure of speech; posture in dancing," from Greek skhema (genitive skhematos) "figure, appearance, the nature of a thing," related to skhein "to get," and ekhein "to have," from PIE root *segh- "to hold, to hold in one's power, to have" (cognates: Sanskrit sahate "he masters, overcomes," sahah "power, victory;" Avestan hazah "power, victory;" Greek ekhein "to have, hold;" Gothic sigis, Old High German sigu, Old Norse sigr, Old English sige "victory").

The sense "program of action" first is attested 1640s. Unfavorable overtones (selfish, devious) began to creep in early 18c. Meaning "complex unity of coordinated component elements" is from 1736. Color scheme is attested from 1884.
scheme (v.)youdaoicibaDictYouDict
"devise a scheme," 1767 (earlier "reduce to a scheme," 1716), from scheme (n.). Related: Schemed; scheming.