LED problem with Z3 Dual

[EGY_falcon]

The notification LED keep blinking with purple color while the screen is off, and I'm sure there's no application with that notification color.
How could I know which application is using that color?

[Qatrium]

Purple is usually Yahoo mail for me.

[EGY_falcon]

I know, but there is no yahoo mail notification at all or any other applications

[_alexdon_]

Have you tried the simple restart?