Wow! That's a super cool bow! I've been working on a kids bow made from a very small diameter piece of osage and it has those same color bands in it, though not to the extent in your bow. Maybe those small diameter trees do something different when they're making wood because they seem to deposit all kinds of cool colors in the wood. The bigger osage trees just make the same color wood from tip to tip without all those interesting colors. YUK! ha ha ha