A color sensor with a plurality of optical sensors in which the number of terminals for connection with the outside can be reduced. The color sensor includes a plurality of optical sensors each provided with a photoelectric conversion element and an optical filter over a light-transmitting substrate. The optical filters in the plurality of optical sensors have light-transmitting characteristics different from each other. The plurality of optical sensors is mounted over an interposer including a plurality of terminal electrodes for electrical connection with an external device. The interposer includes a wiring having a plurality of branches for electrical connection between the terminal electrode for inputting a high power supply potential to the plurality of optical sensors and a wiring having a plurality of branches for electrical connection between the terminal electrode for inputting a low power supply potential to the plurality of optical sensors.