Flag of East Turkestan
The light blue colour (background) is taken from the colour of the sky and is a predominant colour in Turkic culture that represents the sky, essentially the blue represents Turkic peoples. The crescent represents the notion of being victorious (un-defeatable) and is not necessarily an Islamic symbol, in-fact it was the Turks that introduced the crescent into the Islamic world. The star represents the Turkic nation, it is also found on the flag of the White Hun (Hephthalite) Empire and various other Turkic empires and states.