Hello Peter Leroy I think yellow ist the color of danger, and perhaps it goes back to that time. Yellow means: Be carefull. You can't trust this man/woman. I think some insects that are dangerous have the same colors: bees. I have been told we have it from the insect world. In hospitals they often use yellow marks with black triangle to show a blood test can be infected with decease, wich can be contagious. Warnings against computervirus can have the same mark: yellow and black. Jews were wearing yellow David stars as a mark under the 2. world war. I think I have read somewere, that also huguenots, who had been recatholiced during force and pressure were wearing coats with a yellow cross on their back. Sorry I can't remember were I read it. Hanne Thorup Koudal Denmark