The Yei'i'chai - grandparent spirit or "talking God" - is regarded as a special form of Yeii. Their role is to talk to humans and tell them how to live in harmony with all living beings, giving instruction on how best to conserve unnecessary behaviour and actions, instead only using the basics needed for adequate survival.
Rainbow Man (sometimes called Rainbow Kokopelli) is the symbol of the achievement of harmony. Depicted as a Yeii commanding the rainbow, it signifies the gift of beauty to all who live harmoniously.
It's a positive symbol to have around, especially if you're interested in achieving a more harmonious and balanced state of living.