For changing color of the current date from its default theme "a" you can use this:

     <input name="mydate" id="mydate" type="date" data-role="datebox" data-options='{"mode": "calbox", "useNewStyle":true, "themeDateToday": "e", "zindex":2000}'/>

    Hence current date will be in yellow, instead of blue and choosen date can be default blue.

    refer these sites for theming of the call box:

    http://dev.jtsage.com/jQM-DateBox2/demos/fullopt.html
    http://dev.jtsage.com/jQM-DateBox2/demos/api/themes.html

There is no such setting for month text, so for "Tu We" etc override the class as per below:

.ui-datebox-griddate-label {
height: 15px!important;
line-height: 15px!important;
color: green;
}

要删除当前日期的突出显示并仅保持所选日期突出显示，您可以执行以下操作:

To remove the highlighting of current date and only keep the selected date being highlighted you can do this:

但同时保留两者，则需要修改日期框的api代码本身...

But keeping both you would need to modify the datebox's api code itself...