When did witches become green? Is this Dorothy's fault? (or more accurately Victor Fleming)
Witches in Shakespeare famously known as the Weird Sisters were not notable as green. Their claim to fame is rhyming --and ambiguous prophecy-- but not their green skin tone.
Now green is environmental, earth-friendly and the green witches "practice a traditional form of witchcraft in which the
earth, trees, herbs, plants and flowers are consulted for their
medicinal and magical properties." But they are still not physically green.
Back in 1939, there was no such thing as the "green movement" and green was associated with envy, stomach ailments and decomposition. That, and the introductions of Technicolor! likely led to the world making witches green.