The date, Today has a different color than the other dates, this however does not mean that today is always selected, please check the selected date property and you will see that today is not the selected date.
Sadly, last time i checked, this behavior could be changed just by creating a new theme. You can create a new theme using the Visual Style Builder.
Hope this helps, if you have any other questions or comments, please let me know,
Telerik WinForms MVP