I live in Northern Arizona. I know a lot of Navajo people (some prefer to be called Dine') and they've told me a bit about Navajo arrows. I have been told the preferred arrow wood is Mountain Mahogany shoots. The shafts were grooved either in straight lines or in a zigzag line. This represents lightning imparted to the arrow. Sometimes a point and a reverse triangle to represent fletching was added to the grooves. The crest was in front of the fletching and was four bands of red and black alternating. The one closest to the fletching, about 1/4" in front was red, then black, then red, then black, each about 1/2" in width. This is all word of mouth as handed down by their grandfathers and so forth.
Navajo people hang an arrow above the threshold of the front door to protect the house against evil entering. An arrowhead is often worn for protection as well. Certain color arrowheads are used in ceremonies. A traditional bracelet worn by men is called a Ketoh, which is basically an armguard. I have one I wear daily. By the way, the man who makes these is looking to make a trade for a longbow down the road.