In the summer of 2013 I began to build a modular synthesizer.
The panels are roughly Buchla sized. I like the look of Buchla panels, but I had no intention of having compatibility with Buchla synths. Patching is mostly banana jacks, like the Serge systems. Most of the core modular synth circuits (VCOs, VCFs, VCAs, etc) are build on Music From Outer Space PCBs.
For interfaces I have the PAiA Midi2CV8 for controlling with MIDI, and a 1V/Octave keyboard from an old Korg that works with the Music From Outer Space 1V/Oct module.
Since banana jacks are available in a wide variety of color, I thought it would be nice to attach meaning to the colors of the jacks on my synth. This is just a guide and not strictly enforced; I’m sure irregularities can be found among my modules.