Basic knowledge of color science

Additive process Color

Use red (red), green, Blue (blue) three shades for color blending to show other colors. The more light the shade mixes, the more bright it is called the additive process color. The display of TV and computer is based on the principle of additive blending.

Red (R) Green (G) Blue (B) is called the three primary colors of light.

Fig. 1. Addition process Color

Subtraction process Color

Blended with blue (Cyan), magenta (Magenta) and yellow (Yellow) Three pigments to make other colors. The darker the color mixes, it is called the subtraction process color. Pigment tinting, color printer using subtractive mixing principle.

Blue (C) yellow (Y) Red (M) is called the three primary colors of pigments.

Figure 2. Subtraction process Color

Complementary color

When two colors are blended together to produce a neutral color (neutral color), the two colors are mutually complementary.

For the shade, the complementary color refers to the two kinds of mixing will produce white colors. For example, red + green + blue = white, red + green = yellow, so yellow + blue = white. Yellow is the complementary color of blue.

For pigments, the complementary color is mixed to produce a black colour. For example, red + blue + yellow = black, yellow + blue = green, so red is the complementary color of green.

The two colors opposite each other on the color ring are complementary to each other. A color is strongly contrasted with its complementary complement, which produces a strong visual effect.

Three elements of color

(1) Hue (hue)

Also known as Hue. Hue is a feature of a color that distinguishes it from another color. What we usually call "red", "green", "blue", "yellow" refers to the hue of color.

(2) Purity (Chroma)

Also known as saturation (saturation), color. Refers to the degree of purity of the hue. Adding any other colour to the primary color will reduce its purity.

(3) Lightness (value or lightness or brightness)

Refers to the degree of brightness of the color. Adding white to the pigment increases the clarity, while adding black decreases the clarity. In the RGB color System (255,255,255) The lightness is higher than the lightness of (200,200,200).

A system that uses hue, purity, and Mindolai to represent color is called the HSB color model (also known as HSV or HSL). The conversion relationship between the HSB color model and the RGB color model can be referenced.

awn Color System ( Munsell Color System )

People usually describe the color is often blurred, for example, green grass, green and so on. In fact, different people's understanding of "green grass" is slightly different, so we need a system to accurately describe the color.

The Kassel color system was presented by American professor A.H Munsell in early 20th century. The Awn color system provides a numerical method for accurately describing colors. The system uses hue (hue), Purity (Chroma), three dimensions of lightness (Value) to represent color.

(1) Where Hue is divided into red (R), red yellow (YR), yellow (Y) , Yellow Green (GY) , Green (G) , Green Blue (BG) , Blue (B) , Blue (PB) , Violet (P) , Purple (RP) These five main tones with five intermediate tones. Each of these shades is divided into 10 levels (1~10), where the 5th level is the middle color of the hue.

Figure 3. The hue of the awn color system

(2) The brightness is divided into 11 levels, the larger the value, the higher the brightness, the minimum value is 0 (black), the maximum value is 10 (white).

(3) The minimum purity value is 0, theoretically no maximum value. Larger values indicate purer purity.

Figure 4. Awn Color System

such as 5G6/8, where "G" means that the hue is green, "5" is the green middle color, that is, the purest green. The "6" indicates that the lightness is 6, which is moderately bright. "8" indicates purity, the larger the value, the higher the purity.

What is color

Why are the leaves green? The teacher of the elementary school nature class will tell you that this is because the leaves contain chlorophyll, so the pupils are fooled. A more precise statement should be: the chlorophyll absorbs red and blue light, and the most green light is reflected, and the green is seen in the human eye.

The green object reflects the green light and absorbs the other shade, so it looks green. The "White object" reflects all the shade, so it looks white.

Color is actually a very subjective concept, different animal vision system, see the color will be different. For example, the snake eye not only detects visible light, but also senses infra-red, so the snake eye can see a different color than the human eye.

Seven Colors of rainbow?

The primary school textbook tells you that the rainbow is seven colors, have you counted? Newton found that the white light can be broken down into different shades, the legend he from the decomposition of the shade of the number of 7 colors, so "rainbow is Seven Colors" was written into the textbook.

"Seven Colors Rainbow" The default color is discrete (integer), in essence the color is continuously changing (rational number), so the rainbow actually contains countless multiple colors.

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Basic knowledge of color science (RPM)