This field in turn contains a Material node. To change the box's color the appearance field has to be in front of the geometry field. You may have noticed that the Material node is empty. Right now there is no material defined. A diffuseColor field will tell the browser to render the box in a certain color.
Every color is represented by a mixture of red, green and blue color percentages.
Please look at Hello World source file and the Hello World.wrl file again. If you want to move it you have to place the Shape node into a Transform node and translate the Shape node where you want it to be. The Transform node is similar to the Group node with the difference of their translation, scale, and rotation fields. Again, look at the next step of the Hello World source file and the Hello World.wrl file. Now you are in a position to copy the entire box Transform node and paste it as a second and third child.