I can't exatly put a harness in the space im filming in, I heard you can use a box and paint it green?

Chroma keying only have two problems uneven lighting on the chroma key backdrop and the reflected spill on the foreground object. Here are a few tips on how to light your chroma key backdrop. * When lighting your chroma key green screen backdrop, make sure the lighting is even with no hot spots or shadows. Your backdrop lights should be located on either the side or on the back of the subject you are taking video or picture of. You can either use a Quartz light on stand or you can soften the light on your foreground subject. * You should light the foreground subject using a separate light. Do not use the same light used on your chroma key backdrop for the subject. Though the blue or green must be lit evenly, this is not true for the subject. You can actually light the subject dramatically however the trick is not to screw up the chroma key background. This will also reduce the reflective spill *blue or green fringe from the light that is reflected off the chroma key backdrop around your subject. Make sure that your subject does not contain the same color as your chroma key backdrop. * Neutralize any color cast by using a soft back-light on each side of the subject to help neutralize the reflective spill from your chroma key backdrop.