2.0

It may be because of my social science background, or perhaps common sense, that I just don't like putting people in arbitrary categories (especially as few as four) and calling it revolutionary, let alone when two of your categories are pretty much just opposites of each other, and the other two are just there, to describe most people, really. I am nothing if not open-minded, though, so I waited and waited for some evidence, of which there is apparently plenty. Not in this book. This is a consultant's (albeit with years and years of experience) theory/assumed truth about the world. Certainly nothing we've seen from men before.
What really bothered me though is one fundamental contradiction: somewhere in the beginning of the book, the author says it's very rare for people to be just one colour, yet for the remainder of the book going on and on about each colour individually, never paying much attention to what happens when you've got parallel, let alone conflicting colour traits, which, apparently we all do. I might have even been on board with the idea if that was paid attention to, having given it more realism and perhaps even validity.
Other than lengthy explanations of each type of person and predictions on how they would react in a situation (for fun, there is even a teen magazine-style pop quiz at the end, asking questions such as "which colour is more likely to..."), there isn't much material on how to deal with them, as is promised by the description of the book. Other than listening and seeing another person's perspective, which I get for many may be the revolutionary aspect, there isn't much in terms of "finally understanding the people around you." The book claims idiots are people you just don't understand, but then doesn't do much to present them in a good light once you supposedly do understand them. In fact, I felt like judging people of each colour more than I would have without reading this book, so mission failed.
Finally, the presentation of the whole idea as the absolute truth (again, with evidence that apparently exists but was never shown, and no, a couple people you've worked with years ago do not count as evidence) bugs me because... if you believe it, great. You're a swell person, willing to acknowledge your strengths and weaknesses, blah blah. But if you don't buy it, are you... just an idiot in denial? Sounds like perfect marketing/manipulation. If you didn't like the book, you must be offended by what you've learned about yourself and can't handle a little self-awareness. I'm just waiting for you fanboys to call me out for this review about what colour you think I am, and in denial about it.
There were many instances in the book where I felt a hint of condescension about the colours, saying they won't admit things, and are essentially incapable of change, and you have to tiptoe around certain people, because they're red and what can you do.
Long story short, it's a nice idea if you're not really into science, but take it with a pinch of salt. And maybe don't start walking around diagnosing everyone around you because you might upset some people (the unaware idiots).