I understand you are having some print quality issues with your Photosmart C3180 printer. I would like to suggest the guide below for you to use for your troubleshooting steps. I hope the troubleshooting will help rid the purple/grey tint text and bring the true colors back!
If the troubleshooting does not help resolve your issue, I would then suggest calling HP's Technical Support to see about further options for you. If you are calling within North America, the number is 1-800-474-6836 and for all other regions: click here.