After reading tfa I still feel that there is value in this system, but mostly wrt awareness. The course recognizes a spectrum and everyone has aspects of all colors. Many people at my employer are primarily green or blue. During the courses it came out that they (the "introverts") do indeed want to say stuff during meetings but feel like they can't get in on the conversation. This was an eye opener to me, I just thought they didn't want to speak. I now try to pay more attention to these people. That's a win in my book. I also realized that there are people that like to think long before they talk, after a meeting you can revisit them later and they have nice insights which don't come up during a discussion (in contrast, I only have insights during discussions although I may often say things that aren't well thought through, I sometimes call it "thinking against others", typical yellow ;) ).
Like with every framework/mantra/insight/label if you aren't dogmatic about it (looking at you, Agile!), it may provide some value as a model (and models are often incorrect in details and have exceptions, just be very aware of that). I don't really see a better way for someone like me (totally unaware of psychology as a scientific field) to use their insights other than through these simplified, wrong-perhaps-but-useful, frameworks.
Edit: Honestly, to me as a molecular biologist, the whole field of psychology is a model for some neurological truth which is a model again for particle physicists which is a model again for mathematicians... Right (or am I using the wrong model ;) )? We all try to fit some labels on some complex continuum constantly. Sometimes it's pretty useful for our limited minds, and sometimes indeed it may lead us horribly astray. Is tfa an example of the latter? I'm not really convinced.
[0]: https://www.insights.com/insights-discovery-accreditation