Puntuado con 4 de 5 estrellas

Nice add-on, but ico files inside the xpi should have another color,
because the black "CM" in the status bar becomes invisible on some darker FF themes.

Just for those who want to help themselves, like me:
Extract those two ico files from the xpi (after renaming it into zip, temporarily),
change the color to "Olive" by means of "IcoFXPortable" and put the edited files back into the xpi.
Those files, both of them are called "CookieMgr.ico", are located in...
chrome/icons/default
...and in...
chrome/content
...of the archive.
Don't forget to rename the zip back into xpi in the end and
install it just like any other xpi (over the existing installation).

Esta valoración es de una versión anterior del complemento (4.2). 

DONE

This is taken care in 4.3 version. Thanks for your feedback.