You can adjust the ratio of all purpose to whole wheat flour in the tart dough. The final photos in this post show dough with a higher percentage of whole wheat flour than the final recipe. I prepared the tart several times and was happiest with a ratio of 3 parts all purpose to 1 part whole wheat flour in terms of flavor and texture. That ratio will result in a dough that is lighter in color. The photos show the tart dough with a 50/50 ratio.