<h1>#fffと#eeeの間</h1>
<ul>
  <li class="ffffff">#ffffff</li>
  <li class="fefefe">#fefefe</li>
  <li class="fdfdfd">#fdfdfd</li>
  <li class="fcfcfc">#fcfcfc</li>
  <li class="fbfbfb">#fbfbfb</li>
  <li class="fafafa">#fafafa</li>
  <li class="f9f9f9">#f9f9f9</li>
  <li class="f8f8f8">#f8f8f8</li>
  <li class="f7f7f7">#f7f7f7</li>
  <li class="f6f6f6">#f6f6f6</li>
  <li class="f5f5f5">#f5f5f5</li>
  <li class="f4f4f4">#f4f4f4</li>
  <li class="f3f3f3">#f3f3f3</li>
  <li class="f2f2f2">#f2f2f2</li>
  <li class="f1f1f1">#f1f1f1</li>
  <li class="f0f0f0">#f0f0f0</li>  
  <li class="eeeeee">#eeeeee</li>
</ul>

ul {padding: 0;}

li {
  width: 100px; 
  height: 100px; 
  border:1px solid #eee;
  list-style: none;
  text-align: center;
  line-height: 100px;
  display: inline-block;
}

.ffffff { background: #ffffff;}
.fefefe { background: #fefefe;}
.fdfdfd { background: #fdfdfd;}
.fcfcfc { background: #fcfcfc;}
.fbfbfb { background: #fbfbfb;}
.fafafa { background: #fafafa;}
.f9f9f9 { background: #f9f9f9;}
.f8f8f8 { background: #f8f8f8;}
.f7f7f7 { background: #f7f7f7;}
.f6f6f6 { background: #f6f6f6;}
.f5f5f5 { background: #f5f5f5;}
.f4f4f4 { background: #f4f4f4;}
.f3f3f3 { background: #f3f3f3;}
.f2f2f2 { background: #f2f2f2;}
.f1f1f1 { background: #f1f1f1;}
.f0f0f0 { background: #f0f0f0;}
.eeeeee { background: #eeeeee;}