Frédéric wrote:
In fact, I made a mistake : sRGB is about 30% of xyY diagram area. Does this diagram also contain non-real colors ?
Yes, certainly - everything outside the spectrum locus !
Comparing areas in xyY is pretty misleading too - the lack of correspondence with perceptual uniformity in xyY was one of the factors that drove the development of Luv and L*a*b*. Also, xyY gamut diagrams are usually quite misleading because they are a 2D projection of 3D gamuts. Two gamuts may shadow each other (project over the same area), while the 2D projection of their 3D volume of intersection will be quite different.
Graeme Gill.