bootstrap button dark color code example
Example 1: bootstarp btn colors
Example 2: how to change the color of a bootstrap button
.btn-default
{
background-color: #68889E;
color:#FFF;
border-color: #2F3E48;
}
.btn-default:hover, .btn-default:focus, .btn-default:active, .btn-default.active, .open .dropdown-toggle.btn-default {
background-color: #2F3E48;
color:#FFF;
border-color: #31347B;
}