The objective coloured surface was never meant to challenge comparison with any sensuously derived image of external reality. It was meant to stimulate radiant inner icons, whose bodies and features could be quite unrealistic in any ordinary sense of that word. Blue skin or red skin, many heads and arms were commonplace. The density and strength of the colours, the vigour of plastic development could lift the imagery, so to speak, off the page or wall, dissolving it, at the same time interposing a barrier between the inner icon and any comparable visual object. This was meant to produce a higher key or grade of objectivity than any transient reflection on the retina of the eye, a consistent world of the imagination against which visual phenomena seems grey and pale.
Phillip Rawson ‘The Art of Tantra’ Thames & Hudson.