ace-extras.css

.ace-twilight .ace_marker-layer .ace_xref {
margin: -1px 0 0 -1px;
border: 1px solid rgba(255, 255, 255, 0.25);
background-color: yellow;
color: black;
position: absolute;
animation-name: xref-appears;
animation-duration: 1s;
}

@keyframes xref-appears {
  0%   {background-color:black;}
  49%  {background-color:black;}
  50%  {background-color:wheat;}
  55%  {background-color:black;}
  60%  {background-color:wheat;}
  65%  {background-color:black;}
  75%  {background-color:wheat;}
  65%  {background-color:black;}
  100% {background-color:yellow;}
}

.ace-twilight .ace_tooltip {
    border: 0px;
    background-color: wheat;
}

.gutter-box {
    //background-color: wheat;
    background-color: rgba(255,255,230,0.85);

    border: 0px solid green;
    z-index: 20;
    position: absolute;
}

.gutter-pre {
    margin: 0px 1.2em;
}