The colormatch is the (relatively) easy part, assuming the base color of the chip can be matched at all, i.e. it's not Blaze Orange or Arc Yellow or Hot Pink or any other fluorescent Paulson color.
The hard part is using CMYK inks to print something that looks anything like hotstamp foil. What makes a hotstamp look good is that the foil reflects light differently at different angles, and it's REALLY shiny. It's basically impossible to print anything that looks even remotely like real hotstamp foil. I tried it for a while with my printer/cutter but the metallic ink was only "sorta metallic looking" and while it was more reflective than plain ink, it was still not anywhere close to foil levels of shiny.
Another route is to print the background color onto foil media... the problem with this is that you pretty much have to laminate the result, and the makers of solvent-inkjet-printable metallized vinyl advise against full-bleed printing (that is, printing right up to the edge, as you'd obviously need for a faux hotstamp label.) Technical details blah blah blah... it doesn't work (yet?)
That's all based on inkjet printing. Mark (chipshippie) was using different printing technology, direct thermal printing as I recall. (He told me once what model printer he had but I can't find the PM to remember for sure.) I'm looking into adding a direct-thermal printer to my equipment lineup, in any case, specifically to be able to do this kind of thing.
TL;DR -- I can't do it yet, but stay tuned.
