Even backlit and frontlit can have many variables;
time of day
cloud cover effects
While I applaud your effort, my contribution will be down to saying that you can use any of my photos toward the colorizer you would like, as long as it is non-profit.
It is indeed beautiful and hard to capture all this diversity.

We could fake it a little by giving a few levels of randomized transparency or extra brightness (by program I mean). But of course it will never be the same.
I'm not trying to be photorealistic to the limit or in a naive way.
I just want to have a better way of imagining the final result.
So, for example, from that picture I would consider back-lit the three triangles that really shine. I think that would be a good compromise...

Thanks for your offer of using your pictures. The thing is we need then to tile the parts we use to achieve a (more or less) continuous image of 600x300.
The scale of the squares in the ripstop must be correct to the scale of the kite, hence we cannot get a 600x300pixels image out of one single piece of already cut and sewn kite sail.
So I thought that you being a Photoshop wiz could give me a hand

Concerning non-profit, well, I will not make a benefit on this, but if commercial builders wish to use the colorizer then this will be a profit oriented use...
Anyway, Ca Ike has joined the quest. THANKS!
And I guess others will join in too.
Cheers.
I also applaud you for having a 3rd language.
I have enough trouble saying the right thing in my 1 language.

It is easy if you start as a kid. And it surely gets harder as you grow up.
At home we have always spoken Catalan (one Romance language as French, Italian or Spanish):
http://en.wikipedia.org/wiki/Catalan_languageIn society I learnt Spanish (also almost since I was born).
And I learnt English at school (and also a little French... very little)