how to remove background color in bootstrap

need to remove background color of My following bootstrap

#fh5co-hero .fh5co-overlay {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  z-index: 9;
  background: #3b3d40; // need remove background color
  opacity: .5;
}

how can I do it?

#fh5co-hero .fh5co-overlay {
    background-color: transparent !important;
}