Wave length of red light

The color of the wavelength lambda = 685 nanometers is "deep red". The wavelength lambda = 685 nanometers equals the frequency f = 503,852,870,588,235 Hz. 1 nanometer = 1×10−9 meter. 685 nm = 0.000000685 meters. Scroll down to related links and look at "Radio and light waves in a vacuum".