white pepper has its use. I've got black, white, cayenne, red flakes, and dried arbol (before we get into my selection of peppers for chili or salsa). I mostly fiddle around with them for whichever mood i'm in when i'm making tomato bisque (always uses two peppers) or red pasta sauce (always uses 3 peppers), but our lemon butter sauce explicitly calls for white pepper because it disappears into the butter.