Been here many times on the way to rock hunting elsewhere in the southern Utah, northern Arizona region. Good colorful wood can be found in the fields surrounding the Woodruff,Az. to Holbrook,Az. backroad. Actually heading to the area this March for my annual off-season rockhounding/desert mountain climbing trip.
Made a wonderful 3 day loop throughout the Painted Desert- from the entrance where you drop down all the way out near Pilot Rock. It was wonderful. No trails, just wandering and climbing over everything. No wildlife whatsoever though. Highly recommended. Maybe my favorite trip of all time.
Remember to leave the park by 5pm or you're stuck there! Also, remember to bring every single drop of water that you plan on drinking while you're out there because you definitely will not find any.
If I could do it again, I would climb Pilot Rock before leaving and I'd spend way more time out there!