GRN/BLU
Possibly airport colour codes for weather. The military has a system of colour coding e.g. GRN (green) BLU (blue) for fast at a glance weather.
However, I dont think that Verona is military. Should remember, was there last week. Ghedi is probably the nearest military airport (25NM) so Verona is possibly issuing colour codes in weather reports for there benefit.