On the mCore board, there are several LEDs. Some of them are used to provide status information. There is a small LED next to the power supply. There is an LED on the BlueTooth component. Below the mCore name are two sets of LED lights. One on the left and the other on the right. Each is a set of three LEDs. We will use these to learn and understand concepts related to light and color.

Understanding how the human eye works will help understand the concepts behind how LEDs are used to display color. The human eye has two different types of cells to help detect and respond to light. These cells are called rods and cones. The rods work in very low light conditions. Cones work in brighter light conditions. The eye has about six-million cones and about 110 million rods.