While not as colorful as some of the Utah and Arizona slot canyons, this is a mere two hours from L.A. and is very accessible. The hike is easy with the exception of a few ladders to climb and some boulders to duck under. The carved sedimentary rocks within the canyon are consistently gray, but they start showing some reds and greens if you continue the rest of the hike, hence the name Painted Canyon.
The road to this location is about 6 miles, and the surface consists of washboard sand, so be prepared for a 15 mph ride that will rattle your teeth. There are no bathrooms or water in the parking lot, so bring water and a shovel if needed. There isn't even a sign because the parking lot is at the bottom of a watershed that appears to flood out every rain, so make sure to check the forecast before heading out. There is a very high risk of flash flooding in this area. The canyon can reach 115 degrees in the summer, and there are no rangers that will find you; be sure to bring plenty of water.
The hike itself is fairly easy with some bouldering in the very beginning. No trekking poles are required; just your wits. If you are planning on traveling with children, they should be fine if they can climb over a couple of rocks and climb a ladder.
You can camp here as well. Down the canyon, you will notice some pull-offs where other people have camped. You will be able to drive your four-wheel drive vehicle just about anywhere in the canyon. Two-wheel drive vehicles are not recommended, but if you are smart you will be able to make it work. When in doubt, park and walk it first.
Fires are permitted, but you will want to bring your own firewood. There are no designated campsites and therefore no fees, no bathrooms, and no trash cans. Be sure to pack out what you pack in and Leave No Trace.