From Wikipedia

... a Cree woman told her

There will come a time when the Earth grows sick and when it does a tribe will gather from all the cultures of the World who believe in deeds and not words. They will work to heal it. They will be known as the "Warriors of the Rainbow."

... Chief Seattle, who lived from 1780 to 1866:

"When the Earth is sick, the animals will begin to disappear. When that happens, The Warriors of the Rainbow will come to save them.