body {

  padding: 0;
  font-family: sans-serif;
  font-size: 18px;
  line-height: 1.5;
}
body.gray {
  background: gray;
  color: white;
}
body.white {
  background: white;
  color: black;
}
body.blue{
  background: blue;
  color: white;
}
body.blue h1{

  color: white;
}
body.blue section{
  background: blue;
  color: white;
}

body.gray section{
  background: gray;
  color: white;
}


body.white section{
  background: white;
  color: white;
}

body.yellow section{
  background: #e7f3ff;
  color: white;
}



body.yellow {
  background: #e7f3ff;
  color: black;
}




#switcher {
  list-style: none;
  margin: 0;
  padding: 0;
  overflow: hidden;
  
}
#switcher li {
  float: left;
  width: 25px;
  height: 25px;
  margin: 0 5px 0px 0;

}

#grayButton {
  background: gray;
}
#whiteButton {
  background: white;
}
#blueButton {
  background: blue;
}
#yellowButton {
  background: #e7f3ff;
}

section{background:#e7f3ff;}