gecko-dev/composer/base/skin/aboutDialog.css

#aboutDialog {
  padding: 0px 0px 10px 0px;
}

#clientBox {
  background-color: #FFFFFF;
}

#brandName {
  font-weight: bold; font-size: larger;
} 

#detailsBox {
  padding: 8px 10px 10px 8px;
}

#versionField {
  background-color: #FFFFFF;
  -moz-appearance: none;
  border: none;
  font-weight: bold;
}

#copyright {
  color: blue;
  text-decoration: underline;
}

#groove {
  margin-top: 0px;
}