A Brief Analysis of the Phenomenon of Same Color but Different Spectrum

A Brief Analysis of the Phenomenon of Same Color but Different Spectrum

Homochromatic aberration refers to the phenomenon where two color samples can produce the same color sensation but have different spectral compositions.

People have mixed reviews of it! People who praise it value the ability to use different materials to create the desired color, such as fluorescent lamps that emit daylight colors; A color television that can create stunning images by using only three colors of fluorescent powder to emit light. The trouble for those who complain about it is that they may have expected the same color, but when they change places, it becomes different. For example, clothes that they had expected in the mall may not look as good outdoors; During the inspection of qualified product advertisements in the printing workshop, customers found that the colors were severely distorted in certain situations when posting.

The phenomenon of heterochromatic aberration cannot be regarded as an error, it is only based on a characteristic of human eye composition and function. The human eye contains only three types of visual elements - red, green, and blue, with different spectral sensitivity ranges that respond to long, medium, and short wavelengths of light. The brain determines the proportion of red, green, and blue colors observed based on the varying proportions of neural responses caused by the three types of visual elements, resulting in the final color perception. So the color perception is determined by the spectral transmittance (reflectance) of the object and the spectral sensitivity of the photosensitive visual element, which are separated by the spectrum of the light source. This results in different spectral characteristics (source, object, eye), but ultimately consistent color perception, known as the phenomenon of heterochromatic aberration.

The most common forms of heterochromatic aberration include light sources with different spectral distributions having the same color, such as fluorescent lamps and objects with different harmonic reflectance from noon sunlight appearing the same color under sunlight (while the color difference is significant under incandescent lamps), and objects with different spectral reflectance appearing the same color in a small field of view (or different colors in a large field of view).

From this, it can be seen that the "same color" in the same color spectrum can be said to be a dynamic balance. When the conditions change, the balance will be broken, color differences will appear, and troubles will also arise. However, you must accept it and learn to coexist peacefully with it, such as not buying clothes at stalls under streetlights, replacing the lighting in the printing workshop with ones with good color rendering, etc. After all, the same color but different spectra have brought us great benefits. If you don't believe it, please imagine the scene of replacing four-color printing with thousands of colors of ink printing.