You can throw a Raspberry Pi camera and OpenCV at the problem and approach it through software, or you can buy an off-the-shelf RGB sensor and wire it up to an Arduino.

That information is then communicated over Bluetooth to the Arduino which actuates a high-speed electromagnetic gate to force the M&M down the right chute for sorting.

Automotive Grade Device Allows for the Calculation of Color Temperature, Light Source Differentiation, and Placement Behind Dark Cover GlassMALVERN, Pa., April 02, 2025 (GLOBE NEWSWIRE) -- The ...

As a test case, an Arduino Nano 33 BLE Sense was employed to build a demonstration device. Using only the onboard 9-axis motion sensor, the team built an untethered gesture recognition controller.