Outline Color

p.ex1 {
  border: 1px solid black;
  outline-style: solid;
  outline-color: red;
}

p.ex2 {
  border: 1px solid black;
  outline-style: double;
  outline-color: green;
}

p.ex3 {
  border: 1px solid black;
  outline-style: outset;
  outline-color: yellow;
}

p.ex1 {
  border: 1px solid yellow;
  outline-style: solid;
  outline-color: invert;
}