I found a way to root blu advance 4.0 and its really easy . Just install framaroot on your phone and run it.
https://docs.google.com/file/d/0BydMwkccdSNxVmJUdHVPcmptczQ/edit?usp=docslist_api
http://forum.xda-developers.com/showthread.php?t=2130276
https://docs.google.com/file/d/0BydMwkccdSNxVmJUdHVPcmptczQ/edit?usp=docslist_api
http://forum.xda-developers.com/showthread.php?t=2130276