<div class="matgold"></div>

body{
  width:100vw;
  height:100vh;
  overflow:hidden;
  background-color:#343434;
  display:flex;
  justify-content:center;
  align-items:center;
}
div{
  width:20vw;
  height:20vw;
  border-radius:100vmax;
}
.matgold{
  background: linear-gradient(45deg, #c0b283 0%, #c0b283 45%, #FEE9A0 70%, #c0b283 85%, #c0b283 90% 100%);
   background-size: 800% 400%;
  animation: gradient 5s infinite cubic-bezier(.62, .28, .23, .99) both;
}
@keyframes gradient {
  0% {
    background-position: 0% 50%;
  }

  50% {
    background-position: 100% 50%;
  }

  100% {
    background-position: 0% 50%;
  }
}