This coloring page provides a dramatic representation of the distant planet, Pluto. It's a small planet, depicted grey and silver, cast in shadows from the illuminated crescent appearing near one corner of the page. The sun is just beyond the edge of the page, providing this part of Pluto with a silvery glint of illumination. To bring this scene to life, you could use bright blues and oranges to create accents of light in the background, perhaps mixed with muted greys and browns, to emphasize the distance and darkness. On the illuminated crescent, greys and whites could be used to really make the light and shadows stand out. Otherwise, you could go for a more futuristic look and use electric blues and purples to make the scene appear almost alien and dream-like.