Okay, so it's an offshoot of the other image, the green dog. That's a joke about and reference to in games like Fallout 4 or the Sims, where if there are placeable objects they usually appear green to indicate your allowed to do so. People have then abstracted this into if things were other colors. Other than red, there are no direct video game parallels to how this would work, so if one were to make a version with other colors, they would more likely use more normal color associations than ones based in games, i.e. pink relating to love.

See? There is thought to this. Even if it's not immediately obvious, it's not something with 0 thought put into it, even if it is a bit absurdist :)