Airport flags use an orange and white checkered pattern for higher visibility, especially during daytime. These are used mainly to mark construction vehicles,hazards during construction or to temporarily mark other large structures.
These flags serves as a warning to those concerned to be careful of hazards especially if there is an ongoing construction therein such as barricades, stockpiled materials or open manholes.
Same with danger flags , these are used to apprise the people to take extra measures when dealing with hazardous materials. The flag colors are specifically chosen to ensure higher visibility during daytime, even from afar.