When you need to quantify the color of an object ... or you can buy an off-the-shelf RGB sensor and wire it up to an Arduino. Or you can go back to basics and build this reflective RGB sensor ...

Color code: RGB (only colors). RGBW (colors and white). RGB+ CCT (colors and white, with the ability to change from cool to warm white temperature). How many wires? RGB lights require four wires.

Wires run out the far side and through the bamboo stand and connect to a TCS34725 RGB color sensor and an Arduino Pro Micro. The lamp does what you think — hold any colored object up to the ...