CSS3 - rgb-rgba-Color-Opacity

#L1 { background:rgb(60, 80, 100); height:20px; width:500px; margin:20px auto; text-align:center; }
#L2 { background:rgb(60, 100, 100); height:20px; width:500px;  margin:20px auto; text-align:center;}
#L3 { background:rgb(60, 120, 100); height:20px; width:500px;  margin:20px auto; text-align:center;}

#L4 { background:rgb(25, 50, 100); height:20px; width:500px; margin:20px auto; text-align:center; }
#L5 { background:rgb(25, 50, 150); height:20px; width:500px; margin:20px auto; text-align:center; }
#L6 { background:rgb(25, 50, 200); height:20px; width:500px; margin:20px auto; text-align:center; }

#L7 { background:rgba(153, 134, 117, 0.2); height:20px; width:500px; margin:20px auto; text-align:center;  }
#L8 { background:rgba(153, 134, 117, 0.4); height:20px; width:500px; margin:20px auto; text-align:center; }
#L9 { background:rgba(153, 134, 117, 0.6); height:20px; width:500px; margin:20px auto; text-align:center; }
#L10 { background:rgba(153, 134, 117, 0.8); height:20px; width:500px; margin:20px auto; text-align:center; }
#L11 { background:rgba(153, 134, 117, 1.0); height:20px; width:500px; margin:20px auto; text-align:center; }