The cleaning concentrate fragrance is called "Vincenzo Blue":
“a fresh and aromatic citrus fragrance with flowery notes
and a woody and musky base note."
The top note provides the green, citric elements, the heart note the flowery aspects, such as gardenia and lilies of the valley, and the base note provides the woody smell.
In line with these nuances, the contents vary from fleeting to long-lasting. GC100 meets applicable European guidelines on the environmental impact of cleaning agents.
You can find precise information on the contents here.