If by represent, you mean encode, yes! However, they certainly cannot be displayed. Imaginary primaries, which really stands for physically non-realisable colou

If by represent, you mean encode, yes! However, they certainly cannot be displayed. Imaginary primaries, which really stands for physically non-realisable colours, cannot be used to build a physical display that encompasses the Spectral Locus, i.e. more than three are required. Now the reality is that those highly saturated colours are not very common in natural surfaces, a natural reflectance gamut such as Pointer's Gamut or SOCS show that no chromaticities reach the Spectral Locus. Colours outside Pointer's Gamut are typically created with highly saturated emitters such as LEDs or lasers. Because they are spectrally sharp, Observer Metamerism is noticeable and two persons might experience very different visual perception for the same stimulus.