n'th guy out

by Felis Catus

HTML

<div class="container">
  <div class="containee">
    1
  </div>
  <div class="containee">
    2
  </div>
  <div class="containee">
    3
  </div>
  <div class="containee">
    4
  </div>
  <div class="containee">
    5
  </div>
  <div class="containee">
    6
  </div>
  <div class="containee">
    7
  </div>
  <div class="containee">
    8
  </div>
  <div class="containee">
    9
  </div>
  <div class="containee">
    10
  </div>
  <div class="containee">
    11
  </div>
  <div class="containee">
    12
  </div>
  <div class="containee">
    13
  </div>
  <div class="containee">
    14
  </div>
  <div class="containee">
    15
  </div>
  <div class="containee">
    16
  </div>
  <div class="containee">
    17
  </div>
  <div class="containee">
    18
  </div>
  <div class="containee">
    19
  </div>
  <div class="containee">
    20
  </div>
  <div class="containee">
    21
  </div>
  <div class="containee">
    22
  </div>
  <div class="containee">
    23
  </div>
  <div class="containee">
    24
  </div>
  <div class="containee">
    25
  </div>
  <div class="containee">
    26
  </div>
  <div class="containee">
    27
  </div>
  <div class="containee">
    28
  </div>
  <div class="containee">
    29
  </div>
  <div class="containee">
    30
  </div>
  <div class="containee">
    31
  </div>
  <div class="containee">
    32
  </div>
</div>

CSS

.containee:nth-child(10n+5) { color: red; }
.containee:nth-child(10n+6) { color: green; }