I am just bewildered. I had a Canon IPF6100 which worked great with Qimage Ultimate. That printer died and we gave it the funeral it deserved. We now have an Epson Stylus Pro 7890 and the problems begin. Printing photos yields great results. When I print on canvas the color goes all over the place. Have checked with a few friends and some say that I need a RIP. I hope not. I have checked the driver settings 7 ways from Sunday but I always get the same results. I'm just at the end of the rope and hoping that someone has some ideas

Specifically, a blue sky with a magenta cast is printing purple. Other colors are much more vibrant. Especially the magenta

What is the actual paper name/type?

David,
I know you are upset, but you have to narrow down the problem.
You say, absolutely, that other prints from the Epson are fine!!!!  ?
Problem with Canvas!
That should rule out clogged nozzles or a head for the blue.

That leaves two things to test.
The paper or the driver/settings.

Didn't mean to suggest you didn't know what you were doing. Just trying to get to the bottom of the problem.
Still would like to know what paper you are trying.
Is it Epson paper?
If not, then you have to either experiment, or ask the manufacturer of the paper what settings to use, and do they offer a profile for your Epson model.
See if there is a driver update, on line. I just installed 6.75 to try to help.

Fred