Not sure why you not want to use any textures. Also not know if you meant blocks or models when referring to 'box' and why must the surface be black? Well if you are going to use models (I don't use blocks so I can't tell much about those).

Maybe you can change the color by adding a skin to the surface with the skinmanager without adding texture, only edit the material parameters. In the end the easy way would be by using seamless texture with colored edges and it looks better too. However, you said that you didn't want to use those so.

Tried to quickly edit this box in MED with color edge without using textures: