Light bulb connection to the ceiling
Who knows?  Europe is in the middle of  harmonizing their wiring standards.  There's a lot of old and new work out there.    

In one of several old standards, black is neutral.  The new standard is blue for neutral.  What you know for sure is that green is ground.  The other two are hot and neutral.  If your lamp doesn't care, that may be enough.   

If it does care, measure voltage between one of the wires and ground.   The hot will be around 230V to ground.  The neutral will be 0-2 volts.