The scrollable parameter input window allows you to set the diffuse and specular colors of the sphere's material along with the shininess of the material. Coorespondingly, you can set the diffuse and specular colors of the selected light. As with other tutorials, you change anyone of the parameters drawn in green by placing the mouse over the item and with the left button down, drag the mouse up and down.
You can also change a selected item (drawn in yellow) using the Up-Arrow and Down-Arrow keys. The amount added to or subtracted from the selected item is fixed within the program. However, a multiplier is also used in making the change. You may adjust the multiplier through the Page-Up and Page-Down keys. Making the mulitiplier larger accelerates the change that is made to the selected item.