Imaging unit, color measuring device, image forming apparatus, color measuring system, and color measuring method

A color measuring method implemented by a color measuring device that includes a casing having an opening, a sensor unit, a reference chart unit, a cover member, and a calculating unit, the color measuring method comprising:

• capturing, by the sensor unit from inside the casing, a subject located outside the casing via the opening covered by the cover member;
• capturing, by the sensor unit from inside the casing, the reference chart unit arranged on the casing;
• calculating, by the calculating unit, a color measurement value of the subject based on image data of the subject and the reference chart unit that are captured at the capturing.