What does each color in the 4 pair color code mean?

Color codes are also used to identify individual wires in a multi-wire cable, particularly for telephone and digital cables. It is simple to identify both ends of a wire by its color coding. Cable marking is not restricted to single colors. Typically, solid blue, say, may be used for one live conductor, while blue and white stripes may be used for the related earth return which forms a twisted pair with it.