This book, first published in Swedish in 2014, then in English in 2019, and revised and expanded in this 2025 edition, is a classic self-help book. It categorises people into 4 personality types (labelled as Red, Blue, Yellow and Green), which supposedly helps people to understand themselves and others. The author claims that recognising and adapting to the differing behavioural styles will improve your personal and professional interactions.
I found that the book spent too long focussing on workplace examples and not enough on ‘personal’ ones, so I think that the primary audience for this book is professional leaders, though individuals may find it useful too. I’ve spent my whole life thus far not knowing about this system, and in my experience, pigeonholing people ignores the complexity of individuals. Suffice to say that I wasn’t predisposed to like this book, but I persevered, to see what the author had based his system on.
Critics say there’s not much rigorous scientific research behind ‘the system’, but in chapter 18 the author provides a short description of how his system evolved. He mentions the history of Hippocrates system of ‘humours and elements’ that predates modern systems like his own. Hippocrates proposed that human health and personality relied on the balance of bodily humours associated with four temperaments, eg: sanguine (optimistic and social), choleric (ambitious and irritable), melancholic (pensive and analytical), and phlegmatic (calm and sluggish). This ancient system of ‘humorism’ was disproved by modern science, but there’s a legacy of modern personality systems, including the author’s own. It’s based on the DISC personality-type model, which categorises people as Dominant, Inspiring, Stable or Compliant. DISC was researched and devised by US psychologist Walter Marston, who in 1928 researched the behaviour patterns of healthy people. (Jung and Freud had earlier published studies involving mentally unstable people). Many other people since then have fine tuned Marston’s model. In the 1950’s, Walter Clarke developed the DISA concept, which exchanged ‘compliance’ with ‘analytic ability’. The author uses these four main traits, substituting colours associated with these traits for simplicity. The Dominance trait (RED) relates to how controlling a person is in their approach to problems and challenges. The Inspiration trait (YELLOW) refers to how much a person likes to impress and influence others. Stability (GREEN) measures how receptive a person is to change, and Analytic Ability (BLUE) shows how willing someone is to follow rules and regulations. Most people (80%) are a combination of two colours in their preferred behavioural style. REDs and YELLOWs are extroverts, and more active implementers; GREENs and BLUEs are introverts, and more passive and reserved.
To use a colour pun, the system seems a bit ‘black and white’ (and ‘dated’) to me. It doesn’t take into account how many people adopt a different ‘work persona’ in order to fit in with a work or ‘corporate culture’, (although workplaces are thankfully becoming more ‘inclusive’ these days). It also doesn’t factor in the new ‘work-from-home’ reality that many workers now adopt. However, personality test systems can be ‘fun’ to explore whether they’re scientifically valid or bogus, so I decided to continue reading.
The author acknowledges in chapter 3 that most readers will want to launch right into how everything works in practice, so it’s not necessary to skip to Chapter 18 for background unless you want to. As he used various people he knows to illustrate ‘the system’, I started to slot people I know (including myself) into ‘colours’, based on my own perceptions. I found myself intrigued by the author’s anecdotal evidence, and the tone of the book is anecdotal and humorous too, which makes it easy to read and digest. I wasn’t convinced though that the system was particularly ground-breaking or revelatory.
The first sections of the book concentrate on the ‘positive’ and ‘negative’ perceptions of the various colours or personality types. There are no perfect human beings of course, and the best teams are composed of a mix of all traits. (The YELLOWs will come up with new ideas, the REDs will make the decisions, the GREENs will do all the work, and the BLUEs will evaluate and make sure the results are excellent)!
The author spends the next part of the book showing how to use what you’ve learned about the various types, to your (or your business’s) advantage.
In the Chapter on ‘Adapting to others’, the author notes that you can’t change everyone else, and it’s ‘unnatural’ and can even be ‘unhealthy’ to continually adapt to others, but we all do it all the time. He recommends using a system (his system), after appropriate training of course, to cope. As to whether to ‘not be yourself’ is deceptive or manipulative, the author says that you can choose how much or how little to adapt. The advice he gives is pretty common sense really, but it will be useful to those who struggle to adapt to others. It basically teaches how to adapt your messaging to match the communication style of your listener.
There’s a chapter on ‘Group Dynamics, and who gets on with whom. Certain combinations are more suitable than others in terms of working together. Natural combinations include pairing REDS & YELLOWS who will set a fast tempo, set high goals, and motivate others to achieve great things. Pairing BLUES and GREENS will also work as they’ll feel secure with one another, and the decisions (when they eventually make them) will be well thought out. Complementary combinations will work too. BLUES and REDS are both task oriented, one interested in results, the other in process. YELLOWS and GREENS are both relationship oriented. One will talk, one will listen. Greens will ground Yellows, while Yellows will give Greens as much space as they want to work. The two most challenging combinations, that should be avoided where possible, are the pairing of colours with their exact opposite,eg: RED and GREEN, and YELLOW and BLUE.
The Chapter on Written Communication may help when you can’t meet face to face. It shows how different colours have different, distinct writing styles. The trick is to reply in the same style.
There are chapters on what angers and stresses each COLOUR, which can easily be deduced from their preferred behaviour, eg: do what they dislike to anger them, and their stress reaction will be to reinforce and exaggerate their preferred behaviour.
After CH 18 (the chapter that reflects on the history of the system), the book finishes with a chapter of ‘testimonials’ and a short quiz to test what you’ve learned. I got 17/22! Then, there’s a final chapter, using a real life example of an experiment the author did with a group of managers at a conference. He divided them into groups with similar behavioural profiles, and set them a challenge that required cooperation. None of the groups succeeded, proving that diversity is the best way to structure groups.
There’s a list of Further References, and a useful index. There’s also a series of ads for a further 5 books by the author which are variations on this theme, eg: ‘Surrounded by Psychopaths’(or how to stop being exploited by others)! This led me to believe that the author is milking his system like a ‘cash-cow’. While I found this book interesting and entertaining, it didn’t seem ground-breaking, and I won’t be reading any further titles in the series.