Is it possible to replace a portion of the white flour with whole- or white-wheat flour?

Lori, I routinely sub 1 cup of whole wheat flour for about 1 1/4 cups of white bread flour. Whole wheat flour has a higher protein concentration, so it's going to be more dense, so it isn't exactly a 1:1 exchange. Here is a photo of a loaf I baked yesterday morning:

Hi Lori! Yes, for sure. Just keep the substitution small (say 1/2 cup to 1 cup), so you don't compromise the structure of the loaf. With white whole-wheat flour, you might be able to push that quantity slightly higher (say, 1 cup to 2 cups).