Lol, I couldn't give 2 fecks about the picture. The question was whether it was racist or not - I believe it is.So the post says 'One was white, one white and tanned, one mixed race and one black.'
So why are you saying this is racist against one particular group? Seems you are searching for racism where it doesn't exist, don't worry though a lot of people do that these days.
The 'joke' gets its laugh from people's skin colour.
Perhaps next time actually read what was written, not just your interpretation.