"Being colored a particular determinate color or shade is equivalent to having a particular spectral reflectance, illuminance, or emittance, that looks that color to a particular perceiver in specific viewing conditions" (245).
The first two thirds of the book consist of a series of very informative criticisms of objectivist (Armstrong, Hilbert) and subjectivist (Hardin) accounts of color that also serve as a gripping introduction to broad swaths of color science. I'm moved by Thompson's criticisms, to the extent that I'm now on board the relationalist account of color properties (though I'm not sure what to make of Thompson's "ecological" brand of relationalism).
The final chapter contains a fascinating discussion of a little-discussed part of Jackson's knowledge argument, centering on the possibility of perceiving a novel color. Thompson does a good, Dennettian job of thinking the thought experiment through, all the way to trying to imagine what kind of relation a color space containing a novel color would stand to our current, 3-D color space.
eBook Colour Vision