Take a good look at index.html and styles.css and make sure you understand what both are doing.
Goal:
Can you build a basic etch-a-sketch?
A visitor to your site should be able to "draw" with their mouse, simply by moving their cursor around the screen. They should also be able to "pick" a color, using the HTML5 colorpicker.
Solution
You can find a basic solution to this exercise in the solution branch of this repo.