|MadSci Network: Chemistry|
Get thee to a university chemistry library! This stuff is not trivial. Within the last six months or so the Journal of the American Chemical Society has featured a lovely article on "poppy acid" and its dyeing. The Journal of Chemical Education has had at least one cover story on dyeing crystals over the years, possibly more. Find the articles, look at the references. You can go to Science Citation Index to search the articles forward in time - by who references them. It is not just a question of fitting the dye molecules into the crystal structure. They go in with consistent orientation, leading to dichroic effects (pretty!). It was a big deal in the 19th century when synthetic dyes became popular, and it is still a subject of great fun and fascination. But it isn't trivial in execution or understanding. Uncle Al!
Try the links in the MadSci Library for more information on Chemistry.