The Green Sun of Eskanar (Ambient Track for Relaxation and Meditation)

We know that green stars cannot exist. We even know that they could not possibly exist even in another Universe with slightly different physical laws, as weird as that it... But it is possible for some advanced alien civilisation to build a Dyson Swarm containing green filters to make their star appear green. Why? To make it obvious to all other intelligent life that they exist, why else? What better way is there?