The beginnings of direct process color photography date from an 1810 publication by T.J. Seebeck of his experiments using silver chloride and the 1820s experiments of L. Daguerre using various phosphorescent minerals. Further advances led to daguerreotypes which were highly colored but monochromatic. In the 1840s and 1850s, E. Becquerel and C. Niepce de Saint-Victor created images of color spectra with silver chlorides. In 1891, G. Lippman took advantage of photosensitive emulsions (introduced in the 1850s) and the new theory (1868) that interference of light waves caused color to be reproduced in silver chloride plates, and he created fixable, direct color photography, a technology little used after 1907. Indirect methods of producing color images, by reconstruction of the spectrum of color through combination of the primary colors, red, blue, and green, also developed during the early and mid 1800's, along with awareness that human color perception is due to sensitivity of the eye to three primary colors, combined in varying proportions. The photographic color system that evolved into color systems used today was first proposed in 1862 by L. Ducos du Hauron, and involved superimposing primary-color positive separations on a single print. The article includes discussions of some of the technical difficulties, including the need for a three-lens camera until the capability to combine three separation negatives on a single plate was achieved by Ducos du Hauron in 1897. (Abstractor's note: Important historical technical information for photograph conservators.)