In his response to the comments on his article 'How many colors can we distinguish?' by Flinkman and Laamanen, Kuehni points out that their suggestion for just noticeable differences to be defined as diameters rather than radii in related unit difference ellipsoids or spheres lacks the conceptual and geometric logic behind JND solids and is not valid. (C) 2016 Wiley Periodicals, Inc. Col Res Appl, 41, 476, 540, 2016; Published Online 28 June 2016 in Wiley Online Library (wileyonlinelibrary.com).