Books with color illustrations were once rare and costly, but during the nineteenth century advances in color printing technology allowed publishers to include color more frequently. At the same time teachers and government officials attempted to employ graphic displays to facilitate understanding of often abstract or invisible concepts or to show data in a form that could more easily be grasped and retained. The use of color enhanced these endeavors. Dating from 1847 to 1876, the four books discussed here were selected because their authors deliberately chose to replace the written word with color graphics to provide instruction in the sciences and social sciences.