The question
What color is this banana?
It sounds like a question with a one-word answer. It isn’t. You answer with a word. An instrument answers with a reflectance curve — how much light the peel sends back at each wavelength — and a handful of numbers derived from it. A camera answers differently again, and so does the person standing next to you.
Seventeen Eyes follows that disagreement from the first pigments and Newton’s prism to Munsell’s color tree, modern instruments, cameras, printing, displays, and the brain. It asks how we learned to define something as personal as color, and what is left over once the measuring is done.
Why seventeen eyes
In the late 1920s two small British experiments asked seven observers, and then ten, to match colors inside an instrument they looked into with one eye.
Seventeen eyes in total. Their matching data shaped the CIE 1931 Standard Observer — the mathematical stand-in for human vision that still sits underneath color measurement today. When a display is calibrated, a paint is matched, or a print run is approved, that handful of observers from the 1920s is still in the loop.
Who I wrote it for
Anyone who works with color and wants to know where the numbers come from: photographers, designers, printers, colorists, lighting designers, students.
It assumes no background in color science. The book is organized by question rather than by chronology, and each idea arrives through the experiment or the argument that produced it, before any formula does. Eight parts and twenty-eight chapters, from the first ground pigments to the color your brain decides you are looking at.
About the cover
The banana is painted. The science on it is not.
The curve behind it is a measured peel reflectance spectrum: the mean of six measurements of two banana peels, taken from a published spectral dataset. The values beside it are what the CIE 1931 standard observer makes of that curve under daylight — x, y and Y, and the CIELAB coordinates L*, a* and b*.
They describe the measured peel, not the illustrated fruit. Keeping that difference straight is more or less what the book is about.
About me
I am an engineering physicist and lighting technologist. At Philips Lighting I was part of the early effort to explore LEDs for general lighting. I co-founded Xicato, and I am a named inventor on over 100 U.S. patents.
I wrote Seventeen Eyes for everyone who has ever wondered what color really is.