Kuṇḍalinī Awakening
Much of the modern English chakra and kundalini vocabulary comes from one British judge's 1919 translation of a single sixteenth-century Sanskrit text by a Bengali author, supplemented decades later by an influential first-person account. Original Indian sources give varying numbers of chakras and no standard colour scheme at all.
John Woodroffe, The Serpent Power (1919), translating Pūrṇānanda's Ṣaṭ-cakra-nirūpaṇa (1577); Gopi Krishna's first-person account (1967)
The experience of the coiled inner energy rising through the body, and the specific way this experience entered modern English-language vocabulary.