I recommend that you have a nice heart-to-heart talk with your
printer. Find out what the printer would like you to supply. If you
want REALLY accurate color in the final printed piece, you’ll need his
or her help. One way is to just supply a black and white photo for
position on the artwork and “call out” the end color in a PMS Number.
Pantone Matching System (PMS) is a standard method of describing
color ACCURATELY in the printing industry. David Barzilay, Lord of the
Rings (I used to be a printer in another lifetime.)