#open_source_cms, #custom_cms { position: relative; }
div.color_back { position: absolute; top: 0px; left: 0px; height: 100%; width: 100%; background: yellow; display: none; }
div.color_back { filter:alpha(opacity=40); -moz-opacity:0.4; -khtml-opacity: 0.4; opacity: 0.4; }