Bright lights, big fun! Your kit comes with a variety of LEDs. For individual LED fun, you'll get one each of Red, Green and Blue in 10mm diameter size. These look like jellybeans but they're not for eating! You can use your Feather to light up each one in the respective color. They look great and you can see them from far away.
You'll also get a single RGB LED - this special LED is like a smoothie made from the three individual LEDs above! You get one plastic package but with a very very tiny Red Green and Blue LED inside.
Since the LED is all in one, you can vary the brightness of each color to create swirls of infinite color mixtures. It's like mixing paints but you're using light