how to add border around the edge of image png in css code example

Example: how to frame a picture with color css

/* Simple thin border */
img { 
   border:1px solid #021a40;
}

/* Double Border */
img {
   padding:1px;
   border:1px solid #021a40;
}

/* Double Border with different inside border color*/
img {
   padding:1px;
   border:1px solid #021a40;
   background-color:#ff0;
}