Kaleidoscope_(software)
Kaleidoscope is a third party theme manager for System 7 and Mac OS 8, written by Arlo Rose and Greg Landweber. It utilizes a proprietary framework to apply "schemes" to the Macintosh GUI, long before Apple released the Appearance Manager system with Mac OS 8 (later updated in Mac OS 8.5, providing similar functionality using "themes"). Whereas only a few Appearance Manager themes were ever developed, tens of thousands of Kaleidoscope schemes were developed.[1]