White wheat is typically used for lighter/pastry like bread, red wheat is far "heartier" with a stronger flavor. I typically like to blend the two (like 1/3 to 2/3) but ultimately it depends on what you're baking and if you want more rise or more flavor. I don't get good rise at all with fresh ground whole wheat when I am baking a true sourdough without adding some all purpose. Sifting the ground wheat helps but it's a big pain and you lose a lot of bran.