<div>
  <p>1</p>
  <p>2</p><!-- seleccionado -->
  <p>3</p><!-- seleccionado -->
  <p class="hola">4</p>
  <p>5</p><!-- seleccionado -->
</div>

body {
  background-color: #fdfdff;
  height: 100vh;
  display:flex;
  align-items:center;
  justify-content: center;
}

p {
  display: inline-block;
  background-color: #ccc;
  color: #fff;
  height: 60px;
  width: 60px;
  line-height: 60px;
  text-align: center;
  font-size: 2rem;
}

/* :not */
p:not(:first-of-type):not(.hola) {
  background-color: green;
}