Gtk::Label change font

["Diego A. Fons" <diegofons apexar com ar>]

Hi,

I have to display a lebel with particular font face, color and size, but 
i can't get it.
I've tried with set_attributes(), modify_font() and get_pango_layout(), 
are these methods the correct ones?
What must i do to change the font of the label?

Regards,
Diego A. Fons.