Adjust the lighting to simulate atmosphere. in this case, text ( story ) is at the top where it has to be lighten but retain the detail....so, use lighten or brighten instead of erasing. This image concludes the background tutorial in gray scale, though it was not mend to be step by step rather work in progress. It is an actual assignment where most of the coloring process are done swiftly and merged into a single layer for further color adjustment due to time constrain. However, my next post will show a clearer example of layer order. I will try to put up all my previous work in the same manner with more detailed descriptions as I could just to practice being a lecturer again. I will not charge you if you have any question, in the future, I may write a project based reference book complete with the entire file including 3d models and hi-res texture, at the mean time feel free to offer your comment so that I can refind my tutorials. Thank you very much.