Mike, just wanted to confirm your findings about this particular starter and crust coloration. I have only baked a few times with this particular starter and have noticed that it gives a deeper/darker crust coloration compared to my original starter.
Of course my method of baking is not consistent so that may also explain the differences. I usually bake at a stone temp of 650-700 for 2 minutes. I then take the pie up with the metal peel and angle an edge close to the top burner while it's running to darken the edge. I rotate the pie and repeat until I get a golden brown color. Often the thin walled big air bubbles on the top crust will burn. So the inconsistency in my method is that I don't time the process of darkening the rim so realistically the time difference may be greater than I realize. I usually darken the rim to just shy of charring if I can. Of course the bubbles get burnt but that is a sacrifice I'm willing to take. So it's done by "feel" sort of speak and by visualization.
I did note that when I did a starter challenge, both Gotrocks SD starter and your Raisen SD gave a similar and darker crust coloration compare to my own starter. I know you've seen the pictures, but for those that haven't, they can be seen here..http://www.pizzamaking.com/forum/index.php/topic,10811.0.html
Oh one more thought. I was also surprise to get the coloration I did with GR's and the raisen starter b/c I used AP flour in the formulation for the purpose of testing crust coloration. Using my own starter in the past, i would always get a much lighter looking crust when using AP flour b/c of the lower protein content. I thought using AP for this test would accentuate the differences if there were any. And that it did.