Define colors using the Red-Green-Blue-Alpha model (RGBA) with CSS

CSS Web Development Front End Technology

Use the CSS rgb() function to define color using the RGB Model.

Use the CSS rgba() function to set RGB colors with opacity.

Example

You can try to run the following code to set the color with rgba() function

<!DOCTYPE html>
<html>
   <head>
      <style>
         h1 {
            background-color:hsl(0,100%,50%);
         }
         h2 {
            background-color:rgb(0,0,255);
            color: rgb(255,255,255);
         }
         p {
            background-color:rgba(255,0,0,0.9);
         }
      </style>
   </head>
   <body>
      <h1>Red Background</h1>
      <h2>Blue Background</h2>
      <p>This is demo text!</p>
   </body>
</html>