单击任何选项卡时如何更改选项卡的颜色？

这是我的HTML代码

here is my html code

<div id="header">
        <div id="menu">
            <ul class="current_page_itemm">
                <li class="current_page_item"><a href="Home.aspx">Home</a></li>
                <li><a href="JobSeekerlogin.aspx">Jobseeker Profiles</a></li>
                <li><a href="#">Employer Profiles</a></li>
                <li><a href="#">Jobs</a></li>
                <li><a href="#">More</a></li>

</ul>
        </div>
</div>

这里是css代码：

and here is css code :

#menu ul {
    margin: 0;
    padding: 25px 0 0 20px;
    list-style: none;
    line-height: normal;
}

#menu li {
    display: block;
    float: left;
}

#menu a {
    display: block;
    float: left;
    margin-right: 17px;
    padding: 5px 8px;
    text-decoration: none;
    font: 20px Georgia, "Times New Roman", Times, serif;
    color: #FFFFFF;
}

#menu a:hover {
    text-decoration: underline;
    background: #910000;
    color:#FFFFFF;
 }


#menu a:active{
    background: #910000;
    color:black;
}

plz帮我搞定点击任何标签后的颜色变化效果，以便用户知道他们在哪个标签下工作？

plz help me to get the color change effect after clicking of any tab so that user should know under which tab they are working?