Ink painting is a very old, especially in the far east (Chinese ink) used technique. The very beginning of this kind of painting was chinese calligraphy and therefore mostly black and white works.
Today there is a wide range of different ink colours available, black is still dominant, but I personally prefer the shining and brilliant colours. Usually a fine calligraphy brush or –feather is used. Also very important is the selection of good paper: Some literally draw the water in, some have coatings which allows you to create some interesting surface effects….