You can see the demo http://rufai.github.io/buildingx/random_bg_color.html.

In this tutorial, we will:

learn how computers understand the concept of colors
learn about the hexadecimal system and its usefulness to computers
learn how to separate concerns in your code
explore to the world of loops, arrays, and functions as used in JavaScript
use this new knowledge to generate colors in hexadecimal
introduce events in JavaScript
click a button in our HTML code to call our functions
change the body style background-color when the button is clicked



If you want to see more of teachings, check out Xutini - the fun way to learn digital skills.