Full Idea
The bands of colour in a colour spectrum do not correspond to objective discontinuities in light wavelengths. These apparently external bands arise from our biology rather than simple physics.
Gist of Idea
The colour bands of the spectrum arise from our biology; they do not exist in the physics
Source
Roy Sorensen (Vagueness and Contradiction [2001], Intro)
Book Reference
Sorensen,Roy: 'Vagueness and Contradiction' [OUP 2004], p.4
A Reaction
If any more arguments are needed to endorse the fact that some qualities are clearly secondary (and, to my amazement, such arguments seem to be very much needed), I would take this to be one of the final conclusive pieces of evidence.