Starling City (now called Star City) is, of course, the home of Arrow (now called Green Arrow) in the show Arrow. It first appeared in "Pilot" (October 2012). The "You Have Failed This City" refers to a repeated phrase spoken by Arrow on the show, and the arrows and their color should go without explanation
Now, let's be honest. This is mainly just a gag and we'll probably never heard about Starling City again. BUT, this series was in-continuity, which means somewhere out there is a Starling City in the DC Universe that has ties to something involving green arrows.