Unfortunately being point like sources, when imaged they often saturate to white.
I am led to believe one of the techniques Akira Fuji used to enhance star colours in his beautiful wide field vistas was to place a soft focus lens over the objective for the last minute or so of the exposure.
With some trial and error I finally developed a photoshop technique that does the same, and applied it to some old data (what else can you do with this weather! )
The result of my "digital Fuji" processing can be found here...
I like the spectral type diffraction spikes, always makes the 70-80's Dr Who theme start playing in my head...which degenerates into a verse of "Doctorin' the TARDIS" by the Timelords.
Last couple of images have been stunners Peter, always look forward to them.
I like the result diffusers give, in fact I used my one (Cokin diffuser filter) on my friend's camera last night. It's nice to retain that star colour.
I've found the photoshop way of doing it is somewhat effective, depends on the image
Your shot looks OK although I think it's perhaps overdone a bit though, but that comes down to personal taste
)
Ah...that would be due my going through a diffraction phase at the time...or was it fazed diffraction.... 
