I made two loaves of sourdough bread. One was 2/3 whole wheat flour and one was 3/4 whole wheat flour. The latter was only slightly darker with comparable density. Both were relatively dense and sliced well with a mild sour flavor. I don't remember the exact recipe for each but here is my best guess. I have had little success with adding salt to my dough so did not add it here.
1/2 cup sourdough starter (100% whole wheat flour,
water to balance consistency)
3 cups flour
1 egg
milk to balance consistency
I gave them a day and a half to rise/ferment in the oven and baked them at a relatively low temperature (280°F if I remember correctly) for over an hour. I am still very new to baking sourdough but these loaves were so much better and cheaper than store-bought bread that I can never go back.