The problem of color mis-match is not usually the result of a defective system, rather it comes from the fact that there are multiple pieces of image rendering equipment involved in the process, each having different methods and ranges of color management.
First and foremost, the computer monitor is displaying in RGB mode while the printer is printing in CMYK mode. And with sublimation, what comes out of the printer is not the final color as it will shift again during the pressing. It’s kind of like translating French to English to Spanish, you can get the general message across, but rarely is there a direct word-to-word match-up.
It should be noted that a computer screen makes its own interpretation of color, thus what is displayed is probably not the correct color, so spending a lot of time trying to match the output of the printer to what is displayed on the monitor is probably a waste of time. It’s far more accurate to generate proofs for the customer to review and making sure that the correct color management settings are being applied to ensure color accuracy for the final product.
With PowerDriver you can also create reference charts that correlate the final production colors to what you see on the screen. To do this, simply print the color palette that is used by your sublimation printer driver (it includes the RGB codes). Then press it onto a reference substrate such as a coated metal panel. This becomes a visual representation of what the colors will look like in their final form.
Select the colors for your design based on this chart (the output), rather than relying on the screen colors (the input). It may not look correct on the screen, but you will know what it will look like when it comes off the press.
For more advanced color management you might want to invest in a RIP software program which provides very precise tools for managing color and controlling production.