.block_1 {
  color: red;
  background-color: red;
  width: 50px;
  height: 25px;
  border: 1px solid #ff3333;
  content: "red";
  prop: red;
}
.block_1:hover {
  background-color: green;
  color: green;
}
.block_1 .one {
  background: red;
}
.block_2 {
  color: red;
  color: blue;
}
.block_2 .two {
  background-color: blue;
}
.block_3 {
  color: red;
  color: yellow;
  color: blue;
}
.block_3 .three {
  background-color: blue;
}
.block_4 {
  color: red;
  color: blue;
  color: yellow;
}
.block_4 .four {
  background-color: yellow;
}
a {
  background-color: red, foo;
}
ab {
  background: red, foo;
}
.value_as_property {
  prop1: color;
  color: #FF0000;
}