Jumbo pencils! Why on earth would you want to color with a bulky implement when adult coloring calls for finesse? Well, I'm not talking about just regular coloring pencils, I'm talking about the ones that have different colors, usually three, in one pencil. They're also called rainbow pencils or magic pencils (the latter are made by Koh-I-Noor). Of course those two terms don't fit the letter J :-)
I love using them when I am trying to "cheat," when I want to make a picture look like I spent more time on it than I really have. These pencils are especially good for doing backgrounds and for filling in large spaces. The only issue is trying to find a sharpener big enough. I have included a picture below (from the book Enchanted Fairies by Barbara Lanza). The wings, dress and petals were all colored with jumbo pencils. Three different ones, obviously.