Coloring bitmap rock
Picture of a multi-faceted rock transmits the characteristic form of the mark in the rock, for the perception of hand-drawn image. In the life of this contrast is not practical to separate but knowledgeable people there is a similar way, because the way it should be. Easy to paint.
Coloring in a raster (pixel) format. If you use a graphics editor such as adobe Photoshop, then using the fill can easily paint a picture. Outlines for coloring perfect to spend some time coloring on the computer. For children this can be fun and not an obsessive study of the work in the graphic editors, and knowledge of the world in different shades and colors.
Coloring can be printed, and then paint.