$uzunluk=strlen(cagir(sitearkaplan));
if($uzunluk < 7 ){
echo 'background-color:#',cagir("sitearkaplan");
}else{
echo 'background-image:url(',cagir("sitearkaplan").')';
}

echo 'background-color:#000000';

echo "background-image:url(image.png)";