Rgby?

[old_tv_nut]

This is somewhat of a gimmick. Sharp demonstrates it with pictures of brass instruments, which are a more highly saturated yellow.

A display with standared sRGB primaries produces a good range of color, somewhat weak on the cyans and also (but less so) on the yellow saturation. This can be fixed by using only three higher saturation wider gamut primaries. The problem with expanding the gamut by any of these methods is that it is phony to just turn up the saturation on everything unless the source is coded with a higher gamut of color. There are proposed standards for wide gamut color in DVDs and Blu-Ray discs, but I don't think any wide-gamut discs have been released.

People who have bought wide-gamut displays for their computers have run into various problems when software doesn't recognize the color management aspects of this and the color saturation gets artificially increased. Also, since the color on LCDs varies with viewing angle, these variations are stronger when the primaries are more saturated. Using four or more primaries reduces the viewing angle variation, so that is one good aspect of using that method.

You should also realize that the 1931 diagram posted above emphasizes the size of the green/cyan area. Plotted on a uniform chromaticity chart, the missed area in the magenta and purple part is about as big as that in green.