For Color Accuracy and Consistency problems do the following:

-Set the Color Calibration in Printer Setup/Internal RIP Settings/Color Calibration to ON or turn it ON.
-Perform a color calibration and print the plot again (any plots that have already been processed by the Printer will not benefit from the Calibration unless they are sent to the Printer again).
-If the problem persists check the lens and if it is dirty replace the Lens Cover Assembly ( See Lens Maintenance) and repeat the calibrations.
-Perform the Printhead Alignment.
-Perform the Banding Calibration.