I think we are saying the same thing Alex - almost.
The second sentence in Wiki:
The normal sequence of colours is of course, red, orange, yellow, green, blue, etc. The black body temperature substitutes white for green because the the particular mix of frequencies we have evolved to see as white has peak intensity in the green part of the spectrum. A black body cannot get to what we perceive
as green (refer to your colour space chart).
You are talking perceived colours, and I am trying to explain the perceived colours in terms of absolutes (based on my limited background in spectroscopy).
What's your source for the "photon flux" chart? That has me entirely intrigued. As I understand it, and instrument corrected spectrum is directly proportional to photon count. A CCD has a frequency response curve (which often peaks around the green part of the spectrum for pleasing mono images BTW) but once the spectrum is corrected for instrument response, the spectrum intensity has to be proportional to photon count. That's the basis of spectroscopy.
The photon flux chart you have posted looks to me like a raw spectrum captured on a camera with a peak response in the red.