Improving GIF Compression: Features of LZW compression can be used to enhance its efficiency and thereby decrease the size of your graphic interchange format graphics. The strategy is to decrease the number of colours in your graphic interchange format image to the minimum number essential and to remove stray colours which are not required to present the image. A graphic interchange format graphic cannot have more than 256 colors although it can have fewer colours, down to a minimum of two as black and white. Images along with fewer colours will compress more efficiently in LZW compression.