Sourdough getting too brown I am baking loaves of sourdough using this recipe: https://www.theperfectloaf.com/beginners-sourdough-bread/

I cook my loaves in a staub cocette and after the allotted time, they're very, very brown, verging on blackened on all sides. Otherwise, they're great (good crumb, etc). I have tried lowering the oven temperature somewhat (and verified it with a oven thermometer), but by the time they are done internal temp-wise, they're still just as brown. Any advice on how to adjust would be helpful. 

I am at a bit over 5k elevation and in a dry environment, if that matters.
Some people find very brown crusts on sourdough desirable. Judging from the first picture at your link, the author of your recipe may be one. If you don't, one thing to try is to remove the loaf from the cocette something like 10-15 minutes before the end of baking time. This way the crust isn't directly exposed to the heat of the cocotte itself and will brown less. (We started doing this when the bottom crust was getting too dark by the time the top crust, after removing the lid, was browned to our liking.)