When an object absorbs visible red light wavelengths (within wavelength of about 700nm) it is observed be hue. This is explained by the fact that not when red light wavelength strikes the object, not all the light rays are absorbed, but some are reflected by the surface. This reduces the brain perception of the red light as refection is accompanied by wavelength transformation.
Light is described by its wavelength (a physiological property) which is the distance between two consecutive crests. However, not all the wavelengths are visible to our eyes. Human eyes are sensitive to a limited electromagnetic spectrum range with falls between 400 to 700 nm (nanometers) which accounts for only a mere slice within the massive electromagnetic spectrum range. Although the range of light spectrum visible to human eye are limited within 400-700nm, we use the invisible waves which are beyond our vision in a number of ways ranging from x-rays (of short-wavelength) to radio and television broad-wavelengths. Human eyes are made of light sensors which are very sensitive to visible electromagnetic spectrums. When the visible light wave strikes the light sensors in the eyes, the sensor communicate the signal to the brain, which perceives the received signals as being instinct color. The type of the color perceived by the brain depends on the constituents and composition of the wavelengths of the visible light spectrum (Billmeyer and Max Saltzman 12). For instance, when all the visible wavelengths are detected once by the sensor, white light are perceived by the brain or a black color would be perceived when the brain detects no wavelengths. The normal ability of an individual to visualize color or light wavelengths is defined as trichromacy.
Tungsten is an example of Illuminant-A falling in the class of incandescent lighting with a temperature of 2856° K.