<colour> box
Multicoloured boxes were all the rage in the mid 1980's and early 1990's. These devices could be constructed by amateur electronics enthusiasts (usually to exploit the telephone system in some manner). Detailed instructions for making boxes were most commonly distributed as stand-alone t-files on BBSes, some of which were later collected and distributed as part of the Anarchist's Cookbook.
The most well-known boxes include the blue box (a phreaking tool that could generate telephone switching tones) and the beige box (essentially, a home-made linesman's handset). Some, like the blotto box (a device consisting mainly of a Honda generator and an electrical cord with an AC plug on one end and alligator clips on the other) were never really meant to be made. We hope.
The majority of the following boxes no longer work (and some of these probably never worked in the first place). They're presented as a window to the world of the BBS-era deviant.
The following links exist on e2, with precedence given to the Anarchist's Cookbook construction instructions. /msg me if you'd like something added.