Problem with background color of an individual widget

I have been struggling with this for over a month. I have gone through all threads but all in vain. from one of the threads i learned how to change the background color of a single widget but when i use that, nothing happens. look at the css i use and tell me what is my mistake.

div.text-26 {
background-color: #EEEEEE;
}

I am trying to color the widget which contains authors bio. http://www.christiantruthcenter.com