Usually the peak time for fall colors in West Fork of Oak Creek is at about the third weekend in October. The trailhead opens at 8 AM. Expect it to be extremely crowded during that weekend. On the first day when we got there at about 8:30 AM the parking lot had already been full! If you go there before 8 AM, usually you can find parking spots along the road, which is nice because you can start the hike without many people on the trail. Do not forget to display some kind of pass in your vehicle though.
The trail is at the bottom of the canyon. Any time of a day is good for photography because you can always find places that are evenly lit under shade.
The photos of Cathedral Rock, which is my favorite place for sunset, in this page were taken at 4 different locations at Red Rock Crossing. Be sure to give yourself enough time to explore that area.