Colour Compensation
A Colour compensating glass filter is used to reduce the specific colour that your image may have too much of. These colour compensating filters effectively act as light sponges, they are used to absorb excess amounts of a specific colour in a number of different densities according to which filter is selected. By selecting these different densities, very fine adjustments in colour temperature can be made.
The Colour compensating glass filters come in a range of red, green, blue, magenta, cyan and yellow.