Artificial intelligence refrigerator

An artificial intelligence refrigerator comprising:

• a communication unit;
• a camera configured to capture an image of a tray including a plurality of grooves for storing food;
• and
• a processor configured to control the communication unit and the camera,
• wherein the processor is further configured to:
• determine whether a hidden marker is present in a plurality of markers respectively attached to the plurality of grooves from the captured image of the tray,
• based on determining that the hidden marker is present, acquire a position identifier of a groove corresponding to the hidden marker and a reception time indicating that the food is received in the groove,
• transmit the acquired position identifier and the reception time to a server through the communication unit,
• receive determined color information from the server based on the reception time, and
• control a light emitting device provided in the groove to output a color to be displayed on the groove included in the received color information.