In 2016 the TCS3200 RGB Color Sensor was considered the best color sensor out there for Arduino projects. Is this still the case? I can't find any recent recommendations.
I was also wondering whether there are XYZ color sensors available for Arduino. I can only find a handful, all of them without mounting/evaluation board.
In 2016 the TCS3200 RGB Color Sensor was considered the best color sensor out there for Arduino projects.
Such a recommendation is nonsense. It depends on the needs of the project, which color sensor is the best for that specific project. Without a concrete specification of the needs a recommendation doesn't make sense.
I was also wondering whether there are XYZ color sensors available for Arduino. I can only find a handful, all of them without mounting/evaluation board.
Again, you're asking without a clear specification of your needs. At least there are evaluation boards available: AS7261 development kit.
That makes sense, would have been a lot easier though. 
I did find a clear overview of the sensors themselves without LED's, bumpers, etc. And i learned that an IR filter allows color measurements to be made more accurately. So i should be able to figure it out.
XYZ colorsensors with boards are quit expensive.