Bike makers on purpose use colors that are difficult to reproduce - both as transfers and as decals. Thus, you will see many white, gold, silver, and colored foils (e.g. red foil on mavic rims and red / gold foil on normandy and maillard hubs), and other difficult-to-reproduce colors if you are trying to reproduce decals
The japanese company Alps used to make several printers that could print gold and white. However, the quality of printout was mediocre - banding is fairly obvious and it looks like just about any impact printer from about 6 years ago (in other words, it could not come very close to passing as an original decal.) These printers are only available used and supplies (ribbons) for them are out of production.
Inkjet inks are not colorfast in sunlight.
Your best bet is to either use cut vinyl decals from a local decal bureau, or to combine white cut vinyl with spot additive (colorfast) colors printed on top of the decals. Roland makes the printer / cutters, and they cost anywhere from $2500 - $20,000. Thus, it's best to use a decal bureau to make your decals - just email them an encapsulated postscript (eps) file (which can be produced by printing a file from any postscript printer driver), or send them an adobe illustrator file if you have adobe illustrator.
I made some very fine "I n t e r n a t i o n a l" cut vinyl decals for raleighs and it gave my bureau fits trying to weed around these letters. You might tell them you will weed the decals yourself (it takes 5-10 mins with a sewing needle to lift up needless bits of vinyl) to avoid having them reject your job as being too tedious.
The bureaus have several colors of cut vinyls and gold and silver and white inks, but I haven't found a bureau that can do foil decals.
Here are two I bureaus that I know about :
http://www.vcgraphix.com - used to do small runs but no longer does them.
http://www.cegraphics.com/
- Don Gillies
San Diego, CA