The emission spectrum of hydrogen contains light in the infrared, visible and ultraviolet regions. In the visible spectrum, named the Balmer series, the light is red, blue-green, blue-violet and violet.
Applying voltage to a sealed tube of hydrogen produces light. As the light passes through a prism, it is separated into its component colors. The resulting colors are referred to as the emission spectrum. The complete spectrum is called the spectral series, and each range is named for the scientist who discovered it. From lowest wavelength to highest, the series are: Lyman, Balmer, Paschen, Brackett, Pfund and Humphreys. Other series may exist and can be predicted using an equation called the Rydberg formula.