How can I change the color of the first few lines of text using css? Please check my snippet below, and all will be clear. I know that it is possible, but can't remember how... I have to be able to set a certain color for both halves.
.container{
  max-width: 300px;
}
h1 {
  position: relative;
  font-family: verdana;
  color: lightblue;
  text-align: left;
}
h1:after{
  content: "";
  position: absolute;
  left: 0px;
  right: 0px;
  top: 0px;
  height: 50%;
  background-color: rgb(255, 255, 255); 
  mix-blend-mode: difference;
}
<div class="container">
  <h1>This is a very very long text, that should be written in the same element, but with two different colors</h1>
</div>