On the other hand, as an employee who's been on the bottom in that kind of situation, I'm not sure I'd be happy about what you did. Management would be, of course; but I'm talking about the lower-level people. What you really did was take away an excuse for utterly normal bad days, for the little foibles of life, etc. After all, in the old system, if someone on that team comes in with, say, a migraine, and is next to useless for a day while doing what little they can, they can say of a task that missed deadline that day, "Oh, I share my color with so-and-so, I thought that task belonged to them."
It also prevents the ability to take a short mental break and go from focused to seeing the bigger picture. Outlook is easy to use, and it's usually different in color and UI from most other work-related software. It's not fully relaxing, sure, but those 600 hours a year of calendar management that you cut out are now potentially 600 hours more stress for the team members where they're being pushed to accomplish more, no matter whether they were at their stress limit or not.
Interesting scenarios you line up, it's not how I see it though. The public sector of Denmark has been downsizing everything by 1-2% a year for almost two decades, so it is actually the low-level employees who needed this because they are terribly overworked. Obviously management is happy to save that many administrative hours, but they've actually already reaped the financial benefits years ago by law. A cynic might see a bigger cause and effect relationship in there, but I assure you that both our political system, and, our bureaucracy is far too inept to come up with such an elaborate mastermind type scheme.
Also if you have a migraine so bad that you couldn't work, you'd call in sick. In fact, a good manager would send you home sick if they spot you. We have paid sick-leave in Scandinavia. If you have recurrent migraines, we even have national programs, that will pay your workplace a compensation for much of your sick leave.
It also prevents the ability to take a short mental break and go from focused to seeing the bigger picture. Outlook is easy to use, and it's usually different in color and UI from most other work-related software. It's not fully relaxing, sure, but those 600 hours a year of calendar management that you cut out are now potentially 600 hours more stress for the team members where they're being pushed to accomplish more, no matter whether they were at their stress limit or not.