An Orion of a Different Color . ... But the striking picture combines images taken through three separate filters, each designed to record different emission lines - light from Sulfur, Oxygen, and Hydrogen atoms glowing in the tenuous nebular gas. At such low densities , Sulfur and Hydrogen atoms emit red colors while Oxygen glows green. ... NASA Web Site Statements, Warnings, and Disclaimers . NASA Official: Jay Norris. ... A service of: LHEA at NASA / GSFC . ...