Adding CTO (orange) or CTB (blue) gels to your speedlites will change the mood of your image.
Adding CTO (orange) or CTB (blue) gels to your speedlites will change the mood of your image. Sometimes shooting in an environment which is overcast and very blue, adding a CTB gel will warm up the whole environment if you adjust the white balance correctly. CTO gels can also be used to emulate sunlight.