background color rgba code example

Example 1: background color css rgb

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

Example 2: background color cs rgba

#p1 {background-color:rgba(255,0,0,0.3);}

Example 3: css transparent background color

div {
 opacity:25% ; 
}

Example 4: background color opacity

rgba(51, 170, 51, .1)    /*  10% opaque green */ 
rgba(51, 170, 51, .4)    /*  40% opaque green */ 
rgba(51, 170, 51, .7)    /*  70% opaque green */ 
rgba(51, 170, 51,  1)    /* full opaque green */