If color consistency is important for the customer, it is recommended that they do not use HP-GL/2 to print with.

Some media may discolor or change with age. Check that the media is fresh and has been stored correctly.

If the environmental conditions that the customer is printing in change rapidly, you may see changes in the color consistency. By reducing the time the print stays in extreme environmental conditions after being printed (especially very high humidity) you can reduce the color consistency problems.

If you notice that there are color changes between different printers i.e. between the 750C and this printer, it is normal. There will be color differences between HP DesignJet Printers because the other Printers use a different type of ink.