C. W. Leadbeater

Theosophist and clairvoyant claimant, whose The Chakras (1927) illustrated the wheels as spinning discs of colour — and assigned them the rainbow sequence, red at the base rising to violet at the crown.

The second weld, and the one everybody actually pictures. The rainbow is his. The Sanskrit sources give the wheels petal-counts, seed-syllables, deities and elements — they do not give them the spectrum. Every yoga studio chart in the world descends from a 1927 Theosophical book, and almost none of them say so.