Flags are the most important light shapers on a set for me. They can help to control the light and create gradients on a backdrop,they can block light from a complete area and keep the Zone clean of spill light or they can create hard shadows when they are close to a subject and they are perfect for a negativ fill. They are available in many different sizes and when mounted on a C - Stand they are the ultimate Tool. When it comes to extreme coloring with different light sources,i prefer to do some test shots with the x rite color checker / gray card in order to have a reference of the right colors for grading in Post production. Greetings from Paris. Cheers