I found some interesting facts at wikipedia. Different versions, go figure.
Red: for in-school distribution to students
Orange: for sidewalk distribution to Middle/High school students
Digital Camouflage/Desert Camouflage: Military
Dark blue: Law Enforcement Personnel/Firefighters/EMTs
Light green: College/University students
White: Medical professionals (for distribution by the Auxiliary only)
Brown: Personal worker's testaments (for individual witnessing by Gideons)
Light blue: Personal worker's testaments (for individual witnessing by the Auxiliary)
A typical Gideon Bible or New Testament will contain:
a short preface;
an apparatus suggesting Bible verses which may be of assistance in various sorts of trouble;
translations of John 3:16 into a variety of different languages and scripts;
the Bible text itself (the King James Version translation is currently favored), without notes, references, or any other reference matter other than chapter and verse headings — this can either be the full Bible (typical of the copies placed in hotel rooms with the expectation the copy will remain in that room, rather than be taken by any one guest), or just the New Testament, Psalms, and Proverbs (typical of the copies handed out as gifts to particular individuals);
a short description of biblical salvation, with biblical quotations, and generally a place for the reader to sign and date his confession of Jesus (this is especially common in the shorter editions of just the New Testament and Psalms).
Also:
"On Christmas Eve 1968, the astronauts of the Apollo 8 mission read from the first part of Genesis during a live television broadcast from lunar orbit. A Japanese correspondent staying at a Houston hotel while covering the mission called NASA Public Affairs to request a copy of the speech that the astronauts were reading. The Public Affairs official asked where he was staying and then told him that if he opened the desk drawer in his room he would find a book and that he should open it to page one. The reporter found the Gideon Bible and later reported that "NASA Public Affairs is very efficient - they had a mission transcript waiting in my hotel room."<6>"
http://en.wikipedia.org/wiki/Gideons_International