“…Different combinations of color attributes can form more than 7.5 million colors, and the number of colors recognizable to the human eye is estimated to be up to 2.7 million ( 1 ). Color recognition plays a very important role in wide fields, such as disease detections ( 2 , 3 ), chemical reaction processes ( 4 , 5 ), environmental protection ( 6 , 7 ), sensing applications ( 8 ), industrial production ( 9 ), etc. In the past few decades, a great number of electronic apparatuses have been developed for color and optical recognition based on photoelectric effects, such as (photoemissive) photomultiplier tube, cooled charge-coupled devices, or the (junction-based) avalanche photodiode for high-sensitivity detection ( 10 ).…”