== 1931 CIE diagram reversion == 

 Hi - I reverted the image in CIE 1931 color space. I am sorry to see my original image being replaced by successively degraded versions, but I guess I should have immediately copied over the detailed explanation given in the .png file to the .svg file. I have done that now. I hope you see that this was a carefully constructed image, and the "artifacts" are not the result of negligence, but are rather the result of a high degree of accuracy of representation of color, with an unavoidable problem with intensity. 

 I noticed that you have used the other image in a number of places, but I don't want to go replacing them too without a discussion.