Jeannie,
Have you contacted Sawgrass about your color challenges? I am only slightly familiar with the CMYK only driver. You might want to try and print from a different application (i.e. Corel to Photoshop) to see if the colors look better. Odds are there is a setting in the graphic software or printing software that if changed, will improve your color.
Are you running the new RIP software? I ask because the shirts that were sent to me from Sawgrass done with the white ink looked pretty good to me. Here is a link to the post with the pictures -
Sawgrass White Ink - Wash Test Pictures. I just spent the entire day at the RIP manufacturer's office and saw some of the samples they had. I can tell you that the color gamut of the Sawgrass ink is one of the largest when using the correct settings in your graphic software and using the RIP.
Ultimately, there is hope for getting great colors. You just need to figure out some settings. Give Sawgrass a call. Best wishes.
Mark