[chamberinternet]

Check your CSS and have a look for the following entry:

.dialog .title {
    position: relative;
    color: #F3F3F4;
    font-weight: bold;
    font-size: 13px;
    background-color: #A3D6CF;
    border-width: 0px 0px 1px;
    border-style: none none solid;
    border-color: -moz-use-text-color -moz-use-text-color #A3D6CF;
    -moz-border-top-colors: none;
    -moz-border-right-colors: none;
    -moz-border-bottom-colors: none;
    -moz-border-left-colors: none;
    border-image: none;
    vertical-align: middle;
    height: 23px;
    line-height: 15px;
    margin: 0px;
    padding: 0px 0px 0px 18px;
    text-align: left;
    overflow: hidden;

You'll probably have to change the background-color and border-color properties...