SOURCE

<div class="circle"></div>
<div class="circle color-1"></div>
<div class="circle color-2"></div>

.circle{
  width: 80px;
  height: 80px;
  color: #ddd;
  position:relative;
  margin: 10px;
  display:inline-block;
}
.circle:before{
  content: '';
  border: 40px solid transparent;
  float: left;
  border-radius: 50%;
  margin-right: 25px;
  box-shadow: 0 4px 16px;
  opacity: .5;
}
.circle:after{
  content: '';
  position: absolute;
  border: 40px solid;
  border-radius: 50%;
  left: 0;
  top: 0;
}
.color-1{
  color: #01cf97;
}
.color-2{
  color: #ff0000;
}