I have a brand new G7020 and when I print a color test pattern all of them, including black, are washed out. I don't see a way to attach files but I can give you links to the test pattern and a scan of my printout. The difference is dramatic. This is a brand new G7020
Color test pattern: Original color test .
Scan of my printout of above: Scan of my printout
Typically the nozzle test purpose is to determine if any nozzles are blocked. It is not an image quality test.
Verify that the ICC profile and media type selections are correct and print this test image.
Just got off the phone with Canon support. They had me do a clean, a deep clean and a nozzle check. No difference. Then they sent me their image to print, which I did, same results. Washed out colors and the black looked grey. The tech on the phone went off to talk to someone, came back and told me to change the paper setting from "plain paper" to "matte photo" (keep in mind that I am printing this on standard Stapes extra bright copier/printer paper). It was a little better - but I had to feed from the rear, not the front, and it took forever to print.
The tech said it's working as designed!!! Nothing wrong with it. I must say that I find that unbelievable, but that's what she said. So I am sending it back. And I have to pay shipping. I bought this unit as an open box item (Canon verified it had never been used) direct from Canon, by the way.
Now, understand that in addition to printing regular letters with a color logo, we also have to print flyers from time to time, so I needed that color to look right.
I will never buy another Canon product if I can help it.
Interesting development. To make a long story short, I continued hunting around and discovered that if I copied either test image into a Word document, it printed just fine on my plain paper! Only when I tried printing from Windows Photos do I have this problem. And my flyers print fine from Word or from a PDF, the problem is with Windows Photos! In fact, if I open your tif file or my png file in Windows Paint, they also print beautifully.
So I will have to retract my bad-mouthing of Canon!