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.

Off the shelf RGB colour pickers allowing you to extract and objects RGB values can range from a few hundred dollars to thousands depending on your needs.

The DigiPixel is an open source Arduino and Digispark compatible shield with a 64 pixel RGB LED display and six buttons. It comes supplied with its own Arduino library, graphic converter and demo ...

Pi Time is a psychedelic clock made out of fabric and Neopixels, controlled by an Arduino UNO. The clock started out as a quilted Pi symbol. [Chris and Jessica] wanted to make something more around… ...