Date pickers are nearly as difficult as CAPTCHAs. In this case, I’m assuming you’re looping through all the possible dates looking for the correct one, then clicking on that object.

Is it possible to get the properties of the object once located? Since it is a different color, it is possible it uses a different CSS class or, if really old, a different <font color=”gray”> tag within the HTML outer text? You may be able to leverage those differences to know if the date you want is colored gray or not.