What is the way to select colors with red, yellow, blue "RYB" color model rather than RGB?

ByVtdainfo

RGB color is the mainstream in tools and software on the web, CMYK is the mainstream in printed matter, but the first three primary colors learned at school are RYB color model of red · yellow · blue. What are these differences? That is why engineer Dave Eddy has summarized the advantages of using three differences and RYB color, and has released the developed RYB color wheel.

Red, Yellow, and Blue | dave eddy
http://www.daveeddy.com/2014/07/01/red-yellow-and-blue/

This is because the engineer Dave Eddy started listening to a friend saying "I want a real color picker" of a friend. Since Internet and software are full of color pickers and color wheels, Eddy at that time seems that he did not understand the meaning of his friend.

Initially, in educational places such as elementary school, three of red, yellow and blue are called the three primary colors of color, and by mixing these three, every color can be expressed, the more it mixes the darker the color becomes It is said to be black. However, what is used in televisions and computers is red, yellow and blue, not red, green and blue RGB color models. And furthermore, printers and other printed materials use CMYK (cyan, magenta, yellow, black) color models rather than RGB.

ByDome Poon

There are three color models RYB, RGB and CMYK, but if you explain from the difference between RGB and CMYK first, not to become too complicated, RGB will be changed from Red (Red), Green (Green), Blue (Blue) It is a color model to become. Three color lightAdditive mixtureIn order to create a new color by mixing with, it is used in TV monitors and personal computers. Then mixing 100% red, 100% green and 100% blue will result in "#ffffff", ie white.

On the other hand, CMYK uses four colors of Cyan, Magenta, Yellow, and BlackSubtractive mixingBy creating things we will create new ones. Contrary to RGB, when all the colors are mixed, it approaches black, but in the case of printing it is CMYK with black added instead of CMY in order to express black more easily and cheaply.

At this time, subtractive mixing means that this name is attached as 0% blends the brightest as it mixes the lightest, so this name is attached, and on the contrary the more additive color mixture is added, the brighter it becomes, the more it approaches blackIt is named.. Because there is a difference in mixing method, it may not be appropriate to compare RGB and RYB, but why does not bother to use CMY of approximate cyan, magenta, yellow instead of red, yellow and blue RYB Is it?

WikipediaThe following description of cyan, magenta, and yellow is explained below.

The RYB color model precedes the current color theory that "Magenta, Yellow, and Cyan are the three colors best suited for creating vivid colors in a wide range by mixing colors". Red is made by magenta and yellow, blue is made of cyan and magenta, green can be created by mixing yellow and cyan. In the RYB color model, what is expressed in magenta is replaced by red, and what expressed in cyan is replaced with blue.

In other words, red, yellow and blue are not suitable for making brilliant colors than cyan, magenta and yellow. From searching Google search for "real primary colors", search results such as "RYB is dead, long live CMYK (RYB is dead, CMYK survived)" comes out now You can see that CMY is captured as true three primary colors.

This is the color wheel by RYB.


And this is CMY color wheel. These colors that are completely different in vividness from the above do not exist in nature.


However, it is unnatural to use the color called CMY which does not exist in nature without accepting the RYB color existing in nature. So, in order to realize real color paintings on the computer on Eddy, Eddy got roygbiv ((Red / Red, Yellow / Yellow, Green / Green, Cyan / Cyan, Blue / Blue, Magenta / Magenta) We started to create a color wheel using Red / Red, Orange / Orange, Yellow / Yellow, Green / Green, Blue / Blue, Indigo / Indigo, Violet / Sumire).

◆ RYB color model instead of RGB color model

Eddy, who was conducting a survey to create an RYB color model, discoveredUniversity of MinnesotaIt was a paper on RYB mixing by. The paper put value on RYB, it decided the amount of red, green and blue from the amount of red · yellow · blue and made the same color on the monitor.

This is an RGBColor spaceTo the color of the predefined RYB color space. Predefined colors are artistsJohannes IttenIt is chosen from the color wheels made by.

For example, the following cubes have 8 points with RGB color at each corner. Because red is represented by R axis, yellow by Y axis, and blue by B axis, we can see how much RGB color is obtained by moving RYB 3 axes. What happens when all RYB colors exist in a cube and RYB color is expressed as RGB on a monitor by algorithm? I will clarify that.


Using this paper Eddy created the following web service to convert RGB to RYB.

RYB Color Wheel
http://bahamas10.github.io/ryb/


Adjust brightness and ...


Make the division finer or larger.


Change the number of rings.


Rotation of the wheel.


Adjustment of stroke weight.


It is also possible to check the compatibility of colors by masking.


Source code is released on GitHub.

Bahamas 10 / ryb · GitHub
https://github.com/bahamas10/ryb

Note that RYB Color Wheel has a function called Random, and you can express various color wheels by pressing the "Random" button located at the end of opening "interpolation", so you can change color from a color wheel which is slightly different from usual You can also make a selection.