Parallel World’s Bakis Sirros sends word that Serge can offer their shop panels and M-class series M-odules with a more colorful knob scheme:

as Rex says: 

“The colour coded knobs are an option for newly ordered M-class m-odules and Shop series panels and are provided to our STS clients at no additional charge. 

Retrofits to systems already in the field will be handled by payment & 
exchange arrangements between STS clients and myself addressed on per case 
basis.” 

look at the photos section of the SMOG yahoo group (in the m-class series folder) for my CV processor and Wave Processor m-odules that follow this knob colour scheme. 

in detail: 
Black knobs are for offsets and audio (AC) attenuators, and Blue Knobs are for cv (DC) attenuators. 
(the Red knobs are just added to my m-odule for fun, they are not included in the new knob colour scheme.) 

thanks, 
Bakis.

Knob color schemes aren’t a big deal for most modular synth owners – but if (or when) your modular synth starts to get large, color coding can be handy.