Scheme:   monochromatic contrast (base + complement) soft contrast (split complements) double-contrast (2 neighbors + complements) analogic (base + neighbors)

Distance [0 to 60:     0- contrast, 60- triade  ]Use it

Distance [-90 to 90:     (90- tetrade)  ]Use it

Distance [0 to 60:     add the complement  ]Use it