Memasang Kode background changes automatically
Login ke akun blog klik tombol blog baru, buat satubuah link baru  kemudian beri nama sesuai fungsi, klik Edit HTML pada link baru tersebut, hapus semua kode template ganti dengan kode blank template, yang tersedia pada sumber  berikut Get Blank Template   edit background warna sesuai keinginan klik simpan selesai.
Kemudian klik entri halaman baru HTML pada link tersebut.
copy kode dibawah ini, pastekan kedalam halaman baru tersebut dan klik simpan selesai
 <style class="Mys2010-styles">
body {);color:red;height:100%;overflow:hidden;}
body {
  background: #151515;
}
header {
  -o-transition-duration: 0.3s;
  -moz-transition-duration: 0.3s;
  -webkit-transition-duration: 0.3s;
  transition-duration: 0.3s;
  padding:  10px 0;
  position: fixed;
  top: 0;
  width: 100%;
  background: #222;
  border-bottom: 3px solid #dad;
}
/* GRADIEND */
.ap {
position: fixed;
right: 0;
bottom: 0;
left: 0;
height: 60px;
margin: auto;
font-family: Arial, sans-serif;
font-size: 10px;
-webkit-user-select: none;
-moz-user-select: none;
-ms-user-select: none;
user-select: none;
color: #333;
background:  #000020;
border-top: 2px solid #f0f;
z-index: 9999;
} 
h2 {
padding: 15px; 
background: -webkit-linear-gradient(transparent 10%, goldenrod 50%, transparent 90%); 
background: linear-gradient(transparent 10%, #00BFFF 50%, transparent 90%); 
}
/*background*/
#myscript2010 {
  width: 100%;
  height: 100%;
  position: absolute;
  overflow: hidden;
  background: #243763;
  -webkit-animation: bgColorRotate 60s linear infinite alternate 5s;
          animation: bgColorRotate 60s linear infinite alternate 5s;
}
#myscript2010:before {
  display: block;
  width: 100%;
  height: 100%;
  content: '';
  position: absolute;
  top: 0;
  right: 0;
  background: -webkit-radial-gradient(50% 30% circle, rgba(0, 0, 0, 0) 20%, #000000);
  background: radial-gradient(circle at 50% 30%, rgba(0, 0, 0, 0) 20%, #000000);
  pointer-events: none;
  opacity: .8;
}

@-webkit-keyframes bgColorRotate {
  0% {
    background: #243763;
  }
  20% {
    background: #222000;
  }
  40% {
    background: #46344C;
  }
  60% {
    background: #4E513E;
  }
  80% {
    background: #EF8B00;
  }
  100% {
    background: #007F76;
  }
}

@keyframes bgColorRotate {
  0% {
    background: #243763;
  }
  20% {
    background: #283F3D;
  }
  40% {
    background: #46344C;
  }
  60% {
    background: #4E513E;
  }
  80% {
    background: #EF8B00;
  }
  100% {
    background: #007F76;
  }
}
</style>
<div id="myscript2010">
</div>
<div class="ap" id="ap">
<div align="center">
<a href="http://myscript2010s.blogspot.co.id" target="_blank" title="Myscript2010"> 
<h2>
CIBEBER CIMAHI</2></a>  
</div>
<header> 
<div class="Top Title Header">
<div align="center">
<a href="http://sample-mys2010.blogspot.co.id" target="_blank" title="Myscript2010"><b>LET'S STUDY</b>
</div>
</header>
Cat Animated code by. Judith Neumann
Design code is edited by. Mys2010 In Codepen
If you want to directly copy & paste you canDownload Here Background Full Code