Pheromones are what cause an attraction between members of the same species, like a Murmuration of starlings, or a school of fish.

If pheromones were something one could see and were color-coded according to the species from which they came, they might look something like these marks, following their "kind" as they do instinctively in Nature.

Here, color becomes the identifying characteristic and the marks traverse the surface as if engaged in a social network.