add opacity color to background image code example

Example 1: css how to make background transparent

/* Use RGBA */
background-color: rgba(255, 255, 0, 0.75); /* Transparent Yellow */

Example 2: css opacity example

.opacity30 {
  opacity: 0.3;
  filter: alpha(opacity=30); /* For IE8 and earlier */
}

Example 3: set opacity of background image

The following example sets the opacity for the background color and not the text: 100% opacity. 60% opacity. 30% opacity. 10% opacity. You learned from our ...