only for box background color css code example

Example 1: how to change background color in css

body{
  background: lightblue;
}

Example 2: fill color behid text in html

Option 1
display: table;

no parent required
h1 {
    display: table; /* keep the background color wrapped tight */
    margin: 0px auto 0px auto; /* keep the table centered */
    padding:5px;font-size:20px;background-color:green;color:#ffffff;
}
<h1>The Last Will and Testament of Eric Jones</h1>