I have been researching the French army a little more and discover that the Zouave regiment I had painted actually had a green turban at this time , not white as I had painted them. No problem, a stroke of paint and they were altered. But then an amazing thing happened. When viewed from four or five feet away the turban which had been clearly visible simply disappeared. Not only that but the fez and face also blurred together into an indistinguishable blob.
It is quite amazing the way that effectively it creates a kind of camouflage effect. But worse than that figures which were obviously zouaves are now pretty indistinct.

Here then, is vital question. Is historical accuracy the overriding factor? The turbans were definitely green. But they look better in white. Not just more attractive but they convey the style of the figure much better.
I know most of you being civilised and worldly wise will say, "My dear chap,they are your figures do them as you wish." Quite so, but what would you do if they were yours. I am genuinely interested in what is a fairly fundamental question but one which is taken for granted and seldom discussed. I have placed a poll on the left column where I should be obliged if you voted, but please feel free to add additional detail in the comments.