If you are talking about making it blend in with the background color, then you will need to assign a background-color
to it. However, if you simply want it to appear as a square shape, you can try modifying your original code like this: http://jsfiddle.net/Incredulous/6V9ua/
I have removed the duplicate CSS for the img
selector and added px
at the end of -20. Your updated CSS should now look like this:
body{
background:red;
text-align:center;
}
img{
-webkit-filter: blur(20px);
-moz-filter: blur(20px);
filter: blur(20px);
margin:-20px;
}
div{
overflow:hidden;
display:table;
background-color:white;
}
The addition of display:table;
ensures that your div container fits the content within, while background-color:white;
prevents any red from bleeding onto the edges.