A one-step rainbow holographic process implemented with an imaging lens is presented. The generation of color hologram images by this one-step technique is illustrated. The applications of this one-step technique for the archival storage of color films and the generation of pseudocolor holographic imaging are presented. One of the most interesting and important applications of the one-step process is in holographic interferometry. Demonstrations of double exposure, time averaging, and contour generation by this one-step process are included. As compared with the conventional holographic interferometry, the one-step rainbow holographic process is a very simple and versatile technique which yields the advantages of white light readout. The one-step process offers a brighter image, less speckle noise, and better fringe visibility. For multiwavelength and multislit rainbow holographic interferometry, the techniques enable different physical holographic fringe patterns to be displayed in different colors.