@namespace url(http://www.w3.org/1999/xhtml);

@-moz-document domain("youtube.com") {

/* since you removed the "white overlay" on a watched video, this will add it back */
  .watched .video-thumb::after {
    background: rgba(255, 255, 255, 0.5) none repeat scroll 0 0 !important;
    content: "";
    position: absolute;
    left: 0;
    top: 0;
    display: block;
    height: 100%;
    width: 100%;
  }
  .watched .video-time, .watched-badge, div.watched .gridtube_meta_def_container {
    z-index: 10000;
    opacity: 0.9 !important;
  }

/* reposition to top left */
  .watched-badge {
  /* first move "WATCHED" label */
    top: 2px;
    left: 2px;
  }
  div.watched .gridtube_meta_def_container {
  /* if video is watched put resolution label lower */
    top: 20px;
    left: 2px;
  }
  :not(.watched) .gridtube_meta_def_container {
  /* res label to top left by default */
    top: 2px;
    left: 2px;
  }
/* bigger font&element for better visibility */
  .gridtube_meta_def_container, .gridtube_meta_def_container > * {
    font-size: 11px;
    height: 14px;
    line-height: 15px;
    opacity: 1;
    border-radius: 0;
  }
/* colored def */
  .gridtube_meta_def_container[title*="2160"],
  .gridtube_meta_def_container[title*="2160"] .gridtube_meta_def_format,
  .gridtube_meta_def_container[title*="2160"] .gridtube_meta_def_hd {
    background: #000070; /* darker navy blue */
    color: white;
  }
  .gridtube_meta_def_container[title*="1440"],
  .gridtube_meta_def_container[title*="1440"] .gridtube_meta_def_format,
  .gridtube_meta_def_container[title*="1440"] .gridtube_meta_def_hd {
    background: #0000FF; /* blue */
    color: white;
  }
  .gridtube_meta_def_container[title*="1080"],
  .gridtube_meta_def_container[title*="1080"] .gridtube_meta_def_format,
  .gridtube_meta_def_container[title*="1080"] .gridtube_meta_def_hd {
    background: #E70000; /* darker red */
    color: white;
  }
  .gridtube_meta_def_container[title*="720"],
  .gridtube_meta_def_container[title*="720"] .gridtube_meta_def_format,
  .gridtube_meta_def_container[title*="720"] .gridtube_meta_def_hd {
    background: #008000; /* green */
    color: white;
  }
  .gridtube_meta_def_container[title*="480"],
  .gridtube_meta_def_container[title*="480"] .gridtube_meta_def_format {
    background: #FF8C00; /* darkorange */
    color: white;
  }

  .gridtube_meta_def_container[title*="360"],
  .gridtube_meta_def_container[title*="360"] .gridtube_meta_def_format {
    background: #008080; /* teal */
    color: white;
  }
  .gridtube_meta_def_container[title*="240"],
  .gridtube_meta_def_container[title*="240"] .gridtube_meta_def_format {
    background: #808080; /* grey */
    color: white;
  }

/* if not any of the above, but it is HD */
  .gridtube_meta_def_container[title*="high"],
  .gridtube_meta_def_container[title*="high"] .gridtube_meta_def_format,
  .gridtube_meta_def_container[title*="high"] .gridtube_meta_def_hd {
    background: #F30000; /* red */
    color: white;
  }

/* if non of the above are applicable */
  .gridtube_meta_def_container,
  .gridtube_meta_def_container .gridtube_meta_def_format {
    background: #555555; /* dark dark grey */
    color: white;
  }

}