The bumper sticker is spreading awareness of being kind, in that all of us are human, we are the same, and we should give kindness amongst ourselves.
It is arguing that we, as people, should connect and unite under the fact that we are all human, despite differences (as symbolized with the different colors) and spread kindness within ourselves.
It appeals to all audiences as the bumper sticker encourages people to accept each other and treat each other with kindness.
This is most likely pathos because it is appealing to people’s emotions by connecting them with each other. By making them feel like they are connected amongst themselves in that they are all human, they are more likely willing to accept each other for who they are and spread kindness to everyone, despite of their differences. The bumper sticker is trying to say that everyone has their differences, as showcased in the variety of colors, but in the end, it is the commonality that all of the people are humans that connect them all together, thus connecting all the varieties of colors together.