LOl... I avoided this thread until now because of the title. Then I guess curiosity just got the better of me.
I don't think neutering stops the dogs from humping any more than it stops a man. (maybe for a few days) My pup just finished humping the blanket. He's insane.
Also, I think dogs are not color blind. My sister believes that is wrong as well. Her dog will only play with a certain color ball. She can buy the same brand in different colors, but he only likes the one color. Can't remember what color that is though, sorry.
Peace,
Tammy