<style>
body {
background-color: black;
font-family: Monospace;
color: green;
}
.pink-text {
color: pink;
}
.blue-text {
color: blue;
}
  #orange-text{
    color:orange;
  } 
</style>
<h1 id="orange-text" class="pink-text blue-text">Hello World!</h1>