wpf mvvm listboxitem color changing

Question

hi i am developing wpf application using mvvm pattern.

      My question is ---   in my view i have a button .if i mouse enter on that a pop will show list of applications sharing with other
 users(i am hard coding that with 10 strings) . my requirement is  i have 10 items in popup. by default on starting of application .
 the first item (Stop Sharing) should be isenabled =false,opacity=0.4,foreground=white and remaining items(shared application names) isenabled= true and opacity=1,foreground=white
 and if click on other items (means from 2-10) the first item(stop sharing)  foreground should be red and opacity=1,isenabled=true, and later if user clcik
 on first listboxitem the first listbox item(stop sharing) should change to foreground =white,opacity=0.4,isenabled-false.  if possible can any budy share
some working solution!!!