A henna-dyed horse perhaps?

I have somewhere a true story (in an old "Uniformes" French magazine I think) about a North-African cavalry unit arriving in France in 1914, which was ordered to get rid of all its white horses because it was more difficult to conceal them at distance than brown or black horses.
An old Arab NCO was very unhappy with this order because he loved his horse. He said to his captain that he would cover the horse with henna to change its colour so he could keep the horse.
He did that, and ...the horse turned to a VERY shiny copper colour that could be seen miles away

OOops I'm out of topic again
