Could Da Vinci Have Been A Redhead?

It's often mentioned on-line that Leonardo da Vinci had red hair. He would be a great addition to the roll call, however evidence is very difficult to come by, and so far we've only found suggestions that he had hair of a brownish colour at best.

Interestingly though, the following web page suggests otherwise. It states that Leonardo had "long brown hair with a tinge of red". The page is interesting, but quite unorthodox as it suggests that Leonardo appeared in many more paintings than is generally believed.
http://www.kleio.org/en/history/famtree/sforza/323.html#758

The following YouTube video also expounds upon this theme;
https://www.youtube.com/watch?v=lpzs7U0e9AY

Whilst watching the video I noticed the following picture of a red-haired Jesus, apparently posed for by Leonardo.

I'm not too sure the image is actually Leonardo, but it's certainly another ginger Jesus to add to the collection. It would be interesting to know who painted it. The seemingly see-through orb reminded me of the famous Salvator Mundi often attributed to the hand of Leonardo da Vinci. Another Christus with vaguely red hair.