The activity can be run simply as a soldering workshop, but it can also be used to teach additional topics. One can discuss how the human eye works (rod cells and three types of cone cells), discuss how computer screens work (studying screens under a magnifying lens, RGB color spaces), describe the spectrum of light, make fast spinning color wheels, discuss additive and subtractive color mixing, etc.
One can run this workshop on a solderless breadboards if the focus is on color perception and not soldering. If you want to use the custom boards to de soldering, you can cheaply make your own by downloading the “gerber” files and using them to order your own printed circuit boards at any of available PCB manufacturers (for instance seeedstudio.com). Order thinner boards, so that the small USB jack is easier to solder (or just use batteries instead of a USB power supply).