... Credit Copyright: Markus Noller ( Deep-Sky-Images ) Explanation: Why is the sky near Antares and Rho Ophiuchi so colorful? ... Antares , a red supergiant and one of the brighter stars in the night sky , lights up the yellow-red clouds on the lower center of the featured image . Rho Ophiuchi lies at the center of the blue nebula on the left. ... These star clouds are even more colorful than humans can see, emitting light across the electromagnetic spectrum . ... Colorful Star Clouds in Cygnus . ...