Change shadow to other colours

The method changes the colour of the subject's shadow from black to the colour you want.

Place a bare flash with colour flash gel behind subject.

Best if use only 1 front fill light so that the shadow will be obvious. It is good to have the front flash to be able to disperse wide. (Use shoot through umbrella instead of soft box.)

The power of the front fill light should be higher then then bare flash behind the subject so that it can counter the excess colour created by the coloured flash to the surrounding leaving on the a coloured shadow.