You really need to give something to work with here.
PS driver or PCL? (PS is better by far)
Application / File type?
If Acrobat/Reader and PDF, did you let the printer determine the color ala File > Print > Advanced ?
Does it only happen on print or do copies do it as well?
What OS are you printing from?
If you are printing from MS Publisher, export to pdf, even the guy who designed the print system for...
In printing something that is red comes out yellow/green