Several companies have come out with wood-less coloring pencils that you do not need to sharpen. These are pure graphite and can break if pushed too hard. You can also use the side of the pencil to shade.
Koh-I-Noor has produced tri-colored pencils. Each have three pigments in them, so it is probably best to use them in abstract, zentangles, or geometric designs. I am never sure what color will show up when, so every stroke can be a surprise. Watercolor pencils are water soluble, and can be used as a wash, or for adding details. The paper used makes a difference as well. I have included a book on watercolor pencil techniques, for those of us newbies.