I'll provide a concise description of the flag of New Caledonia without discussing its symbolism:

1. Colors: The flag of New Caledonia has three main colors:

   • Blue (#0055A4)
   • Red (#EF4135)
   • Green (#007E3A)

2. Aspect ratio: The flag's aspect ratio is 3:5 (width:length).

3. Geometric properties and measurements:

   • A blue field covering the entire background of the flag.
   • A large red horizontal stripe along the full width, equal to one-third of the flag's height, located at the center of the flag.
   • Two green, diagonal stripes on each side of the red stripe, slightly narrower than the red stripe, extending towards the corners of the flag.
   • The red horizontal stripe and both diagonal stripes form a large Y shape.

Note that this description applies to the Kanak flag, which is one of the two official flags in New Caledonia, alongside the French tricolor flag.