<div class="container-fluid"  style="border-bottom: 2px solid grey; ">
  <div class="row">


    <div class="col-sm-4 col-sm-offset-4" id="quadradocolorido">
      <p style="display: none;" id="acertou"></p>

    </div>
        <div class="col-sm-4 col-sm-offset-4">

      <input id="imp" >

      <button onclick="cenas()">cenas</button>

    </div>
  </div>
</div>
*****************
<script>
  function cenas(){

  document.getElementById("acertou").style.display = "block";
  var teeste = document.getElementById('imp').value;
  if(teeste){
    document.getElementById("acertou").textContent = "acertou";
    document.getElementById("quadradocolorido").style.backgroundColor = "green";
  }else{
    document.getElementById("acertou").textContent = "errou";
    document.getElementById("quadradocolorido").style.backgroundColor = "red";

  }

}
</script>