Difference between RGB & CYMK
Firstly, we have to ask how do human perceive color? Human see by allowing light that reflected off objects into their retina. The light is then absorbed by cone cell located inside retina to send the information (in the form of electrical pulses) needed to brain to analysis what color the eye have seen.
Firstly, we have to ask how do human perceive color? Human see by allowing light that reflected off objects into their retina. The light is then absorbed by cone cell located inside retina to send the information (in the form of electrical pulses) needed to brain to analysis what color the eye have seen.
The subject is not so simple however as white light actually composed light of different wavelengths combining together. This can be seen during formation of rainbow (created through a process called refraction) where seven distinct color of rainbow can be seen when white light is spitted through a process called refraction.
Therefore human eye actually see by having cone cell that are most sensitive to certain wavelengths of light being hit by light of that wavelength. Human have what we call trichromatic color vision which perceive colors by using three independent channels for conveying color information, derived from the three different cone types.
Each type of these cone cells respond best to certain wavelength of light. Light of long (especially 560 nm), medium (530 nm), and short (420 nm) wavelengths will be perceived as Red, Green and Blue respectively by human brain. Interaction between at least two types of cone is used to produce the ability to perceive color.
With at least two types of cones, the brain can compare the signals from each type and determine both the intensity and color of the light. For example, moderate stimulation of a medium-wavelength cone cell could mean that it is being stimulated by very bright red (long-wavelength) light, or by not very intense yellowish-green light. But very bright red light would produce a stronger response from L cones than from M cones, while not very intense yellowish light would produce a stronger response from M cones than from other cones. Thus trichromatic color vision is accomplished by using combinations of cell responses.
RGB
Based on human’s trichromatic color vision and named after the three primary addictive colors, is an additive color model in which red, green, and blue light are added together wavelength for wavelength, to make the final color's spectrum. In this color model, colors are created by superimposing the three component (each with different intensity) of that color on a black screen (reflection of white screen also work). All zero intensity result in black, all full intensity result in white and if the intensities of all component is the same, it will result in shade of gray. Colorized hue resulted from the different intensities of the component color, its saturated depending on the difference of the strongest and weakest of the intensities of the primary colors employed.
When one of the components has the strongest intensity, the color is a hue near this primary color (reddish, greenish, or bluish), and when two components have the same strongest intensity, then the color is a hue of a secondary color (a shade of cyan, magenta or yellow). A secondary color is formed by the sum of two primary colors of equal intensity: cyan is green+blue, magenta is red+blue, and yellow is red+green. Every secondary color is the complement of one primary color; when a primary and its complementary secondary color are added together, the result is white: cyan complements red, magenta complements green, and yellow complements blue.
This color is commonly used electronic device that capable of emitting their own light, thus able to control which light to emit at which intensity to create the desired color.
CYMK
The CMYK color model (process color, four color) is a subtractive color model, used in color printing, and is also used to describe the printing process itself. CMYK refers to the four inks used in some color printing: cyan, magenta, yellow, and key (black).
The CMYK model works by partially or entirely masking colors on a lighter, usually white (normal color of paper used in printing press), background. The ink reduces the light that would otherwise be reflected. Such a model is called subtractive because inks “subtract” brightness from white.
This was because unlike electronic that are capable to create light, printing press has to create a mixture of paint that will reflect only the light that is needed to create a color a human brain will interpret as the desire color. Unlike RGB color model where white is the combination of all primary colored lights and black is the absence of light, in the CMYK model, it is the opposite: white is the natural color of the background, while black results from a full combination of colored inks.
Comparisons between RGB displays and CMYK prints can be difficult, since the color reproduction technologies and properties are so different. A computer monitor mixes shades of red, green, and blue to create color pictures. A CMYK printer instead uses light-absorbing cyan, magenta and yellow inks, whose colors are mixed using dithering, halftoning, or some other optical technique
