Dog signs at the Boardwalk

As always during the summer months, my favorite place to hand out is the Boardwalk in the Beach. This year, I have noticed some new dog signs all over the place. I am clueless what they suppose to represent, the red signs are on lamp posts along the boardwalk showing a dog with a collar. I assume it means you cannot have your dog off leash there. The are off leash show the same dog on yellow which I guess it means OK to have your have your dog off leash there. Except these signs are far from clear: if the city is using red for NO, why they are using yellow for YES? There is a visible collar on the dog but neither show a leash. Anyways I thought it kind of confusing, as dog owner myself I would just ignore them because they do not explain anything to me other than that they little cute pointless signs all over the place.