background color

body {
  background-color: green;
}

body {
  background-color: lightblue;
}
 

body {
  background-color: rgb(255,255,255);
}

html,body {
  background-color: red;
}

//javascript type css:
document.body.style.backgroundColor = "blue";
// or inline css:
<div style="background-color: blue;"></div>

/* To apply color to background you have to use 'background-color' property and value of property is color name. */
html,body {
  background-color: blue;
}

div {
 opacity:25% ; 
}

body {background-color: coral;}

 background-color: blue;