It is supposed to be the color of a corpse that is starting to rot.
Thanks for the unpleasant thoughts. I guess I shouldn’t have used the word sense. Rotting flesh is a whole different color than a horse.
So what I mean to say is that I don’t actually visualize a green horse.
Saying rotting flesh brings to mind a whole other image.
What a yucky thing to visualize before going to bed. yuck!