Alkaline phosphatase, cresyl violet, Nissl stains—such are the components that make up the histological rainbow, the stains used to visualize various anatomical and cellular features in tissue samples. Drs. Roger C. Wagner and Fred E. Hossler of the University of Delaware have put together a nice website, complementing their mammalian histology course, that showcases a large number of histological samples in all of their colorful brilliance. Color histological sections are organized by tissue type or organ system, although they are only one of the interesting features of this website. The PowerPoint presentations for each lecture are also posted on the site, and there are also some transmission and scanning electron micrographs. For the more motion-oriented reader, there are a number of animated sequences of 3-D biological models, although one will need to be patient as the large files load.