The Gaussian Spectrum node generates colors using a Gaussian distribution spectrum.
Wavelength - The mean wavelength approximation between 380 nm - 720 nm (with a range from 0 - 1). Lower values appear bluish, and higher values (around 700 nm) appear reddish.
Width - When set to 0, almost no color is visible. When set to 1, the color spreads thin over a large space, and the texture appears faint.
Power / Brightness - The texture's brightness.