“A wind direction indicator shall be constructed so that it gives a clear indication of the direction of the wind and a genreal indication of the wind speed”
“Where a combination of two colours is required to give adequate conspicuity against changing backgrounds, they should preferably be orange and white, red and white”
“A wind direction indicator at a heliport intended for use at night shall be illuminated”
Annex 14, Volum II of ICAO international standards