Initially, the plan was to use color to group related controls. For example, in Braids: white = frequency, turquoise = timbre, fuchsia = color. Grids: white = coordinates, turquoise = fill, fuchsia = clock speed. Edges: white = frequency, turquoise = amplitude.
This didn’t work well on more recent modules, which have small attenuverters (and thus no need to color two knobs with the same color to group them together), and more than 3 dimensions of control or more than 3 families of parameters.