Planets Online Coloring Pages. Color pictures, email pictures, and more with these Planets coloring pages. Click on any picture of Planets above to start coloring. When the online coloring page has loaded, select a color and start clicking on the picture to color it in.lanets Online Coloring Pages. Color pictures, email pictures, and more with these Planets coloring pages. Click on any picture of Planets above to start coloring. When the online coloring page has loaded, select a color and start clicking on the picture to color it in.