I really can't answer your question, but here is a link where you can find information about stamping on cookies. I have wanted to try it, but it is back on the long list of want to try that some day. Hope this helps:
http://www.sweetstampen.com/index.asp
Sorry, I misunderstood your question, on the link I gave you, I believe they stamp on fondant, but it is a neat website anyway.
I've never stamped color onto cookies iced with royal, but I have stamped piping gel onto them and then sprinkles the piping gel with colored sugars or dusts. The dress cookies in my photos have one that is a white dress with silver dust that was done that way.
I would assume that since that works, stamping color on would too....
Yes, it works. I find it hard to do though (probably because I really don't have the right tools). You are not supposed to use a wooden backed stamp because it is not food safe. The site that linedancer gave you is the place to go to find out about stamping. Good luck!
Quote by @%username% on %date%
%body%