These two studies were done from real human tissue, as part of my Medical Illustrator education. Dissection study from preserved specimen is a good demonstration of anatomical variation one can see in each individual, and how it differs from canonical schematic illustrations. But it is very recognizably an image of dead tissue, with all color and plumpness of living tissue gone. The autopsy tissue study of a kidney reflects actual colors of the organ. Didactic illustrations are usually only loosely based on this color scheme, since clarity of functional relationships and distinction of form superseeds photorealism.