.popover {
    background: #4d4d4d;
    border: 1px solid #4d4d4d;
    color: white; 
}

.popover.left > .arrow:after {
    border-left-color: #4d4d4d; 
}

.popover.right > .arrow:after {
    border-right-color: #4d4d4d; 
}

.popover.top > .arrow:after {
    border-top-color: #4d4d4d; 
}

.popover.bottom > .arrow:after {
    border-bottom-color: #4d4d4d; 
}