Remove the White Squares from Zoom in the posts

Hi!
I set the background color of the page and I copy this:
.widget-front .round-div {
border-color: #f7e4ba; /* Change #000000 to background-color */
}

This code remove the white square of featured page but don’t remove this effect in the image of the post.
I try this code:

.tc-thumbnail .round-div .row-fluid .span4 .thumb-wrapper{
border-color: #f7e4ba; /* Change #000000 to background-color */
}