Step 1

Open a new document, 600 by 600. Make your background and forground black/while. Go to filter-render-difference clouds.

Step 2

Go to image-adjustment-invert ( the colors will switch the colors) then go to image-adjustment-levels. Move the middle arrow to the far right

Step 3

To change the color of lighting do the following-go to image -hue/saturation, once the hue/saturation box comes up check of colorize, move the arrows to whatever color you want.

To add more then one lighting. Create a new layer repeat all of the above, on u have that part finish, on your second lighting, with the layer menu selected choose--screen instead of normal.