I promise to stop writing about these Ghias soon! It's just that I found a nice silver-blue one rather more quickly than I had expected. Apart from some flaking chrome on the bumpers it is in excellent condition and was not at all expensive.
The photograph here shows clearly that this is a distinctly different colour, the darker blue being the shade that I seem to encounter most on my travels.
A colleague did send me a link to an even more 'silver' shade so I shall keep on the look out for a lighter shade too but I am pretty certain that reports of just silver are based on either repaints or maybe a factory sample.
Now I just need to find that very deep shade that I have seen here and there. In fact I may need both the deep turquoise and also a rich deep blue that I think I have seen but I couldn't tell whether it was a repaint in that case.