Write the `generateClasses` function. It creates a `<style>` tag inside the `<head>`. It should generate one class for each color in the `colors` array, which sets the `background` attribute like so:
Write the `generateColdShades` function which creates a `<div>` for each color of the `colors` array, whose name contains `aqua`, `blue`, `turquoise`, `green`, `cyan`, `navy` or `purple`. Each `<div>` must have the corresponding generated class and display the name of the color, like following:
The function `choseShade` is triggered when clicking on a `div`. Write the body of this function. It accepts the shade of the clicked element as an argument, and replaces all the classes of all the other elements by the chosen shade.
