With this characteristically forthright statement, delivered in an address entitled 'Why Colour?' to the Royal Photographic Society in December 1932, Madame Yevonde set out her whole approach to the new medium with disarming candour and finality.

The VIVEX process, with which Madame became acquainted around 1930, was a subtractive process, a variant of Trichrome Carbro, which in turn was derived from the Carbon process. It employed three negative plates - cyan, magenta and yellow, for the full colour range - which could be exposed in a number of ways. Madame Yevonde settled upon two methods, the first of them involving an automatic repeating camera back which fitted onto the back of an ordinary plate camera. The negative plates were moved in succession by clockwork behind appropriate colour filters during exposure, which typically lasted some 2 - 3 seconds. The obvious drawback of this arrangement was that any subject movement during exposure meant that the three plates did not exactly match, leading to registration problems at the printing stage. The second method of exposure was by means of the specially designed 'one-shot' VIVEX Tri-Colour Camera (Model A) in which the three plates were all exposed simultaneously, thereby eliminating at a stroke any possible differences between the images on the three plates.

The three negative plates were processed separately to produce the separations required for printing. The three images were then printed one on top of the other by hand and eye to obtain the final print.

It was at this stage that the unusual sophistication of the VIVEX process became apparent. During processing, the gelatin layer obtained from each plate was transferred to a thin gelatin sheet, to act as a temporary support during printing. This gave the printer an opportunity to correct any faults in registration by coaxing the image back into correct registration again, always provided that the degree of movement had not been excessive. Similar faults in registration arising from occasional refraction problems with the one-shot camera could also be corrected in the same way. In addition, the process provided almost unlimited scope for retouching to remove any unsightly blemishes.

The fact that the process employed three colour plates which were exposed and processed separately gave Madame Yevonde the freedom to indulge in all manner of different forms of colour manipulation, and she was arguably the earliest and most accomplished exponent of this arcane art prior to the digital age. She experimented tirelessly with coloured cellophanes over the lights and lens to produce a variety of different effects - notably in the 'blue' Goddess images - and further manipulated the colour by adjusting the balance of the three plates at exposure, and by raising or lowering the level of a given colour on printing.