A tooth shade scan system is provided that identifies tooth shades for a patient's tooth. An electronic database of tooth shade information for a shade guide may be stored. The database may include shade information based on tooth regions (e.g., the incisal, central, and cervical). A system operator may be shown an image of a patient's tooth on display equipment such as a computer monitor. An application running on the system may display dividers that the operator can manipulate to divide the image of the patient's tooth into regions. The regions may correspond to regions for which specific tooth shade information is available in the database. Values representative of a limited number of color characteristics for a region as a whole may be determined from the image. Corresponding categories of color characteristics may exist in the database, which is then used to identify tooth shades by region for the patient's tooth.