I may be saying the obvious here, but have you done a clean head and head alignment. If so and it printed ok on normal paper I would suggest it could be the paper. Try a different paper. Also check your monitor and printer calibrations...
Free Utility Color Calibrates Your Monitor
You should really calibrate both your monitor and printer as these go hand in hand. Many monitors come with a calibration set and this should be your starting point. If you don't have it, go the manufacturer's web site to see if you can download it. They may also have custom calibration software available. In addition to your monitor controls, it's possible to alter color settings using your graphics card or software applications like Adobe Gamma that comes with Photoshop. That sounds great but it often causes users to fall into the trap of calibrating several times using all available options. This is a mistake; calibrate only once otherwise you will be over compensating. The most important thing though, is to understand what you are doing. That's why I recommend users visit Norman Koren's website [1] before doing anything. It's a bit technical but color calibration IS technical. If you find Norman's site a bit overwhelming then this site [2] may be better. Both of these sites have links to software and reference images, but for the calibration process itself, most casual users would be better off using a little freeware program called the 'Monitor Calibration Wizard' [3]. It will give results that are more than adequate for most applications. A final word: getting color right sounds like a simple issue but it's not. It's a matter taken very seriously by graphics and photography professionals and they dedicate an appropriate amount of time to addressing the problem. Indeed many professionals calibrate their equipment every six months or so to ensure that the quality is always at its best." Freeware, all Windows versions, 771KB.
[1]
http://www.normankoren.com/makingfineprints1A.html#Monitorsetup
[2]
http://www.e-cobo.com/stockphotos/quality/calibration.php
[3] [url]http://www.hex2bit.com/products/product_mcw.asp
[/url]
Hope this helps. If you are using Photoshop then set your printer setting to RGB Adobe (windows) and set your Gama to 2.2.
Hope this helps
moonseye