[jQuery] Orange Color is not Visible in Slider Range

Hi!
Iam newbie to jQuery UI. Kindly visit following link :
http://vibersol.com/ajaxsearch/
There is slider (with ranges) on top. I just used all default files
and settings. What I am doing wrong that Orange color is not visible
between range. Can some one guide me how can Orange Color (Default)
can be put/visible there.
Thanks in advance