I'm sorry to hear about the issues that you've experienced and I'll be happy to offer any assistance that I can.
Printing on plain copy paper versus a plastic film label material is quite a bit different mechanically - some printer models handle it better than others, and it is pretty common to see some differences in color duplication between the two material types. This is due to how the heat from the fusing unit dissipates into the label material - plastic material will generally hold heat for longer periods than paper-based materials, which can cause the toner being applied to appear somewhat differently.
Unfortunately, I don't have access to your specific printer model for testing, but I was able to locate the user manual for your printer model online. I know you had mentioned adjusting printer settings with no success, but there are a couple things that may be worth trying if you haven't yet.
According to the manual there are three settings under the Printer Maintenance section that could potentially change the print quality on your labels: Paper Density, Adjust Transfer Roller, and Adjust Fusing Unit. I would try adjusting all three of these settings to "Label". If you are still unhappy with the color duplication on your labels I would try adjusting all three settings to "Coated".
The manual specifies that the default settings might not give the best output for all material types. Pages 93 and 94 in the user manual give tips on how to make manual adjustments to these settings as well, in the event that the default settings are not ideal.
Some trial and error may be required to get the colors just right. I'd be happy to send out a sample packet with some additional sheets if you need them for testing purposes. If you are interested in receiving some additional sample sheets please just let me know.
Edited by user Tuesday, September 20, 2016 2:56:03 PM(EST)
| Reason: Not specified