var a = document.getElementsByTagName('a');
var dom = document.location.toString().match(/:\/\/[^\/]+/).toString().replace('://','');
for (i in a){
    if (!isNaN(i.toInt())){
        var href = a[i].getAttribute('href');
        if (href.indexOf('://') > -1){ // fqdn, maybe not this domain
            var test = href.toString().match(/:\/\/[^\/]+/).toString().replace('://','');
            if (test != dom) {
                a[i].setAttribute('target','_blank');
                a[i].style.color = '#c6161d';
            }
        }
    }
}