As I look back on this, there were things I would have done differently. For example, it would have made more sense to combine all of the different grouts in one big bucket so that, regardless of the eventual color, it would all have matched. Next time.
Here then are photos of this wonderfully organic and "green" shower. I absolutely love it! It makes me feel like I am someplace in Italy, a place I hope to visit some day. In the meantime, the shower will have to do.