I had to review Doug's column again for your post.Chemical lights come in two basic modes;high intensity,short life,and low intensity longer life(12hours vs.1).The high intensity are often orange for two reasons;first it is the most visible color to human color acuity,and second one of the less common colors in vegetation,snow etc.As I write this my horses are running in a pasture full of California Poppies! Green is just the most common color readily available in my area.The only color of any real difference is blue.People who suffer epilepsy may have a seizure in response to rapid strobe lights or blue light in darkness.<br><br>