The sandpaintings' principal colors-white, blue, yellow, and black-remind Navajos of the Four Sacred Mountains bordering their traditional homeland. These mountains and some of their associations are:
White Shell Mountain (Sierra Blanca Peak, Colorado): white-east-dawn
Turquoise Mountain (Mount Taylor, New Mexico): blue-south-day
Abalone Shell Mountain (Mount Humphreys, Arizona): yellow-west-twilight
Coal Mountain (Hesperus Peak, Colorado): black-north-darkness
The bird is the liason between the earth, the red colour, and the spirit world. The bird is embroidered in the same colours and the body is filled with fly-stitches. Thank you Anneli for this idea.
Their are a number of explanations on the internet I choose this one from the collectorsguide, if it is the wrong one please let me know.
Have a colourful day and may all your relations walk with you.