In most of my photos, I usually look nice and clean. However, that is due to the fact that I get weekly baths. I groom myself just like other cats do, but my tongue can't keep up with the oil my skin secretes. Since I have no fur for the oil to distribute itself through, the oil builds up on my skin.
In the two photos below, I am very dirty and in need of my weekly bath. If you click on the photos to make them larger, you will really be able to see what I mean. The oil and dirt are especially noticeable on the pink areas of my skin.
In this first photo, you can see the oil on my neck and chest. You can also see some of the oil on my belly.
In the next photo, you can really see the oil on my belly! If you click to make it larger, you will also be able to see the oil in the wrinkles on the side of my face. The oil really accumulates in all of my wrinkles, so my humans have to very carefully and thoroughly wash wherever I have wrinkles.
In the second photo, too, if you look closely at the larger version, you might notice some brown on the fleece blanket I'm sleeping on. That brown is oil that has rubbed off of my skin. Don't worry, both the blanket and I were washed not long after these photos were taken.