Ambient continued:  Example (7b) shows these differences in a different light so to speak.  The cans on the left are the lowest settings and those on the right are the highest.  Drag a can onto your background.  Press the Alt + Ctrl keys, click and drag to create copy of it.  Run the settings from minimum to maximum on both sliders to see how different they are.                                                   

Light Color:  Click on this box and a Color palette will appear (notice the orange Preview box) (8).  I chose an Orange color for the light (8). Using this palette you can select any color you wish. Example (8b) shows how the color appears on the alfalfa.