Achieve precise white balance with various filters to affect the white balance and color with filters color correction and graduated filters. Nikon Orange Filter (O56) subtracts green, blue and ultraviolet. Nikon Amber A2 filter subtracts blue thus correcting bluish colorations that sometimes affects daylight film. The mid A2 warms scene shots on cloudy days or in the shade. Nikon Blue B2 filter subtracts red while cooling down colorations. The B2 is used with daylight film to remove the reddish tinge from sunrise and sunset shots.