Thomas Frognall Dibdin’s 1817 Bibliographical Decameron was lavishly illustrated with images of medieval manuscripts, including full-page facsimile engravings in, as he put it, “one sober tint, either brown or black.” He was very aware of color, and like many manuscript scholars of the time, often described the colors of his originals in lavish detail that clearly sought to capture the imagination of his readers. When Dibdin was writing, color technologies were limited. By the time Henry Shaw created the engravings for his 1866 Handbook of the Art of Illumination, on the other hand, chromolithographic reproduction was becoming ubiquitous, making Shaw’s decision to use monochrome wood engraving for this book a bold choice. And while Shaw championed the superiority of monochromatic reproduction over the often “dull” and “heavy” attempts to render the glory of medieval illumination with modern color techniques, his work, like Dibdin’s, minutely instructs observers in how they might imagine the color of the originals. Even as both men extol the excellence of their reproductions, their writing is haunted by what cannot be pictured, and this haunted gap is, it turns out, a preoccupation of facsimilists across time and technologies. This talk will explore how facsimilists from the eighteenth to the early twentieth centuries thought and talked about color. Technology, imagination, and cultural expectation come together as producers and consumers of facsimiles wrestle with what a “faithful” facsimile really is.