Each body gesture, sign, word usage, pitch, eye movement and other communication methods may have different meaning from place to place, some are universal others are just local, when we see such kind of variations we call them localization.
It is the same for rainbow in the sky. In some places rainbow is a sign of unity , Good luck and greetings. For example if you see a rainbow in Ethiopia's sky we call it Yemariam Mekonen or Mary's Cincture/Belt. It is a sign of God's presence in the area but not as others are trying to interpreting. That is a wrong interpretation. Bet way is before you put your own weak interpretation study about people's values, culture and tradition. Also respect their tradition is a key to be respected