Early forms of color photography used additive techniques to record colors, as opposed to the subtractive techniques of modern processes. Additive processes employed a microscopically fine screen of red, green and blue filters, and a silver image which allowed varying degrees of light through these filters. Research centered on the Finlay Plates housed at the Australian War Memorial which were taken in the final years of World War I. In order to understand more fully the role of the silver image and its contribution to the color and the form of the final photograph, a number of positive silver images were made from an original World War I Finlay negative. Initial experiments were aimed at establishing the role of the developer in forming the image and the effect these would have on the final color. Further investigations centered around manipulation of the already developed image to alter its microstructure and therefore the overall color of the final Finlay Plate. It was found that the microstructure of the monochromatic silver positive was very important in determining the color of the plates, and that the color potential of plates could be established for experimental comparative purposes.