common.css

.rainbow {
  color: #00bfff;
  -webkit-text-fill-color: transparent;
  background-image: -webkit-gradient(linear,left top,right top,color-stop(0,#f22),color-stop(0.15,#f2f),color-stop(0.3,#22f),color-stop(0.45,#2ff),color-stop(0.6,#2f2),color-stop(0.75,#2f2),color-stop(0.9,#ff2),color-stop(1,#f22));
  background-image: gradient(linear,left top,right top,color-stop(0,#f22),color-stop(0.15,#f2f),color-stop(0.3,#22f),color-stop(0.45,#2ff),color-stop(0.6,#2f2),color-stop(0.75,#2f2),color-stop(0.9,#ff2),color-stop(1,#f22));
  background-image: -o-linear-gradient(transparent,transparent);
  background-image: -ms-linear-gradient(transparent,transparent);
  background-image: -moz-linear-gradient(transparent,transparent);
  -webkit-background-clip: text;
  background-clip: text;
}