Why is Preview printing blurry text when there is colour in a document?
I printed and then scanned the test document using my Canon MX850 (an ink jet printer with scanner, about 6 years old).

It's not perfect, but I don't see the issues (blurry text between the yellow boxes, purple stripes) that I see in your Ricoh version.

So I'd guess that the problem is the Ricoh drivers.

OS X 10.9.5
Printed using Preview 7.0 (826.4)
Printer is Canon MX850
Printed using default settings (Print Quality: Standard)
Scanned at 300dpi.