(CPs) are passports of countries no longer in existence, e.g. former British or Dutch colonies such as Rhodesia, Zanzibar, Dutch Guiana, Netherlands East Indies, &c. These states have usually changed their names, typically after gaining independence. Thus, British Honduras is now Belize, while Zanzibar fused with then time Tanganyika to become today's Tanzania. Upper Volta became Burkina Faso, and of course, some of the most recent examples include the USSR and Czechoslovakia.
When American travelers became prime targets of hijacking and international terrorism on an ever increasing scale, Camouflage Passports were invented to afford them some additional security. The idea was to present a potential hijacker with a valid looking, non-American document to hide one's identity. Thus, it was supposed, terrorists might pick someone else to harp upon, to take hostage or even to kill.
Camouflage Passports were never intended to be used as actual traveling documents at border controls etc. Even today, we strongly advise against using them in lieu of bona fide passports when crossing from one country to another: not all border officials are as a dumb as they may seem, while you will certainly be inviting no ends of hassle if you give them the impression of willfully hiding something from them.
In some countries this may be a felony, but even where it isn't, people caught traveling with "counterfeit documents" are always viewed with strong suspicion. You may even face an espionage charge, depending on the current political situation, and you shouldn't count on your home country's consulate or embassy personnel being particularly happy about having to cater for someone pretending not to be one of their citizens in the first place. Thus, their diligence and eagerness to help could prove to be severely wanting - meaning that you may have to spend weeks and months wasting away in a foreign jail, which is no fun thing at all!