Here are some helpful solutions for the common causes:
The natural sugars in dairy products enhance crust color. Substitute milk for the water in your recipe.
Sugar plays many roles in yeast breads, including browning. The most important role of sugar in baking yeast breads is to provide "food" for the yeast. Yeast breads without sugar will not rise properly, if at all. The amount of sugar called for in non-sweet yeast breads should not cause a problem for most diabetics. If, however, you still wish to use a non-caloric sugar substitute instead of sugar, use a recipe that has been specifically developed for the specific sugar substitute. The crust color most likely will be light.
Salt can lighten the color of baked bread. Try decreasing the amount of salt by 1/8 to 1/4 teaspoon.
Unlike most baked products, shiny aluminum pans are not the first choice of expert bread bakers. Breads baked in shiny metal pans often need to bake longer. The choice of expert bread bakers is a dark heavy-gauge steel pan.
Oven thermostats can vary over time, requiring adjustments by the baker or calibration by a professional. To insure the correct temperature each time you bake, always use an oven thermometer. Place it in the center of the oven. Adjust oven dial up or down to correct the oven temperature.