# File lib/color/palette/monocontrast.rb, line 174
174:   def color_diff(c1, c2)
175:     r = (c1.r - c2.r).abs
176:     g = (c1.g - c2.g).abs
177:     b = (c1.b - c2.b).abs
178:     r + g + b
179:   end