Thank you for your prompt reply.
My reasons for attempting to adjust it are, at low contrast levels the flesh tones take on a mauve/pink colour and none of the customer adjustments will compensate for this. The greyscale as delivered lacked green. If Sony use this expensive equipment to set these levels I fail to understand why all of the drives are set to an equal level and all of the background controls are also equal. Could my set have missed the setup process?