Transparent Colors

CSS3 supports RGBA colors. The RGBA declaration allows you to set opacity (via the Alpha channel) as part of the color value. A value of 0 corresponds to a completely transparent color, while a value of 1 corresponds to a completely opaque color. To specify a value, you can use either a real number between 0 and 1, or a percent.

personnel:before {
    display:block;    
    padding: 1em;
    font-size: 1.8em;
    content: "Employees";
    font-weight: bold;
    color:#EEEEEE;    
    background-color: rgba(50, 50, 50, 0.6);
}