Funny you should be saying this... Just last Monday, I took a shot of Eta Carina with my piggybacked Pentax, proudly put it into my astro files, then tried to print it. What looked terrific on the screen, came out completely green on paper. I have Canon Pixma 800 and use top qual photo paper.
Tried again after processing it in Iris - hopeless.
Eventually I got an almost acceptable print by printing directly from the SD card into the printer - bypassing computer completely. Colours on the Pixma are black, cyan, yellow and magenta I think.Also, from the SD card, a 4 x 6 print was different to a 5 x 7 - the larger the print, the greener it was
It all sounds depressingly complicated and expensive , this photography lark - I may soon be selling all my imaging stuff, telescope etc and just using the Mark 1 Eyeball and LB 12"