The sound difference depends on many factors when the coils are wound. There can be different tolerances in the plastics such as creme or black and the space needed for winding the coil. I find that the tolerances in the bare magnet wire diameter, insulation thickness, number of turns, winding tension, hookup wire, magnet tolerance and grade, magnet gauss, pickup position, pickup height, type instrument and wood, tolerances in the volume and tone controls, capacitance in the guitar cord are some of the many combinations which make each pickup sound different.

I’ve heard great sounding guitars with double black, zebra and double creme bobbins. Maybe they saw Jeff Beck with exposed double creme bobbins and figured it would make them sound like him. The color of the bobbins was determined by the lack or shortage of a particular color. When the molder ran out of black to finish a run of bobbins, they called Seth Lover and asked, “can we run the bobbin in creme” and Seth said “go ahead”. The sound of a pickup is very subjective to each individual.