How does the SPIKE Prime Color Sensor work? Pro Preview

Two things are responsible for the colors we perceive - light and our eyes.

The most common light sources, such as a lamp or the Sun, give us what we call white light. White light contains all the colors within it. Each color and shade corresponds to a different amount of energy in the light, from red to violet, which makes up the visible light spectrum. Light sources often emit more light than what our eyes can see; these are called infrared and ultraviolet lights. While humans can't see them, many animals can perceive ultraviolet light.

So, what color are these objects?

Red, right? Well, yes and no.

When we see something as red, it means that it reflects red light and absorbs all other colors of light. In a sense, the object is anything but red! The same principle applies to most colors. For example, a blue background reflects blue light and absorbs the other colors. Black and white are the two extremes - objects that appear black absorb almost all light, while objects that appear white reflect almost all light!

The SPIKE Prime Color Sensor lights up in white when connected, providing its own source of light. In the middle, it has an actual sensor that collects data from the light reflected off the surface below it, then calculates the color. For consistent detection, the sensor needs to be about 1 or 2 LEGO units away from its target. Here's how it looks: