WPF- MVVM - Listbox databinding and changing color of item

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 should be isenabled =false,opacity=0.4,foreground=white and remaining items isenabled= true and opacity=1,foreground=white and if click on other items (means from 2-10) the first item foreground should be red and opacity=1,isenabled=true, and later if user clcik on first listboxitem the first listbox item should change to foreground =white,opacity=0.4,isenabled-false.  if possible can any budy share some working solution!!!