字符串拼接字体颜色不同

$("#dao_pam_msg").append(
'<div id="'+val.msgId+'"><span class="span1">'
+ title_mes + '</span><span class="'+
(val.msgId == 1 ? "span4" :"span2")+'">'
+ val.num + '</span><span class="span3" onclick="showDetail(\''
+ val.msgId + '\')">'
+" Show Detail"+ '</span></div>');

根据msgId判断，span4是颜色1，span2是颜色2