D50 definition

Hi folks,

It was recently pointed out[0] that the XYZ values for the D50 
illuminant given on, for example, Matlab[1] or Bruce Lindbloom's site[2]

|[0.96422, 1.00000, 0.82521]|

differ from the once specified by the ICC

|[0.9642, 1.0000, 0.8249]|

||

"In ICC v4, the requirement was introduced that the media white point of 
a Display class profile shall be equal to D50 (i.e. [96.42, 100, 
82.49])" [3].

I assume the authoritative source is the CIE. I will check my books this 
evening, but can anyone shed light on the discrepancy (and the correct 
value)?

[0] https://github.com/w3c/csswg-drafts/issues/2492#issuecomment-377913660
[1] 
https://www.mathworks.com/help/images/ref/whitepoint.html?s_tid=gn_loc_drop
[2] http://www.brucelindbloom.com/index.html?Eqn_ChromAdapt.html
[3] http://www.color.org/whyd50.xalter

-- 
Chris Lilley
@svgeesus
Technical Director @ W3C
W3C Strategy Team, Core Web Design
W3C Architecture & Technology Team, Core Web & Media