These folks sure look mighty brown to me. Not that it matters one whit, except it’s just a bit of an odd choice to make by the artist. If assume they were intended to be be “white” folks. If so then I guess that’s what riding in an open convertible will do to you, in that era before sunscreen. A precautionary tale.
As a contrast, here’s what happens to white folks’ skin if they chose an Olds wagon instead: