.how-to-buy {
  background: #008000!important;
}

.how-to-buy {
	background:#ffff00;
  animation:myfirst 5s;
  -moz-animation:myfirst 5s infinite;
  -webkit-animation:myfirst 5s infinite;
}

@-moz-keyframes myfirst {
0%   {background:#ffff00;}
50%  {background:#008000;}
100%   {background:#ffff00;}
}
 
@-webkit-keyframes myfirst {
0%   {background:#ffff00;}
50%  {background:#008000;}
100%   {background:#ffff00;}
}