What is color contrast?

1, simultaneous comparison and continuous comparison

When two or more colors are put together at the same time, both sides will push each other to their complementary colors. For example, when red and green are put together, red is redder and green is greener; Black and white together, black is darker and white is whiter. This phenomenon belongs to the simultaneous contrast of colors. Hue contrast, purity contrast and lightness contrast all belong to all parts of the whole. Continuous contrast phenomenon and simultaneous contrast phenomenon are caused by visual physiological conditions, both for one reason, but they occur under different time conditions. Simultaneous contrast mainly refers to the contrast effect of colors at the same time, and continuous contrast refers to the contrast of different color stimuli under different time conditions or in the process of time movement. For example, we look at a piece of red for a long time and see that everything around us is green; When we adapt to the warm light environment and suddenly come to the normal light, we will feel that the color is cold. This kind of visual afterimage belongs to the continuous contrast phenomenon of colors. Mastering the law of continuous color arrangement can make designers use it to enhance the impression of visual communication or reduce the visual fatigue caused by intense work.

2. Tone contrast

The juxtaposition of different colors shows the difference of outstanding phases in contrast, which is called hue contrast. For example, compared with cobalt blue, lake blue is green and cobalt blue is purple. Comparatively speaking, the characteristics of these two colors are more distinct.

Tone contrast includes:

Primary color contrast: Red, yellow and blue are the three most extreme colors in the color circle, showing the strongest hue temperament, and the contrast between them belongs to the strongest hue contrast. If primary colors are used to control colors, people will feel a very strong color conflict. For example, all countries choose primary colors as the colors of national flags; Peking Opera facial makeup also uses strong three primary colors to highlight the characteristics of the characters.

② Intermittent color contrast: orange, green and purple are mixed from the original hue, and the hue contrast is slightly softer. The colors of plants in nature are mostly intermediate colors. If the flowers are yellow-orange, purple, green-orange and green-purple, they are lively and have natural beauty.

③ Contrast of complementary colors: The colors at both ends of the diameter of the color ring are complementary colors. The best way to determine whether these two colors are complementary is to mix them to see if they can produce neutral gray. Otherwise, the hue components must be adjusted to find the accurate complementary color. The juxtaposition of a pair of complementary colors can make each other's colors more vivid. The most typical complementary color pairs are red and green, yellow and purple, blue and orange. Yellow and purple are the most prominent complementary colors because of the strong contrast between light and shade and the great disparity in color personality. The blue-orange pair is in the middle of the contrast between light and dark, the contrast between cold and warm colors is the strongest, active and vivid, the contrast between red and green is close, and the contrast between cold and warm colors is in the middle, and the mutual emphasis is very obvious. The opposition of complementary color contrast makes the hue of the opposing sides more distinct.

④ Contrast of adjacent tones: The juxtaposition of adjacent basic tones on the color circle, such as red and orange, yellow and green, orange and yellow, is called the contrast of adjacent tones. It belongs to the category of weak tone contrast. Its biggest feature is the obvious unified tonality, which does not lose contrast and change in unity.

⑤ Hue contrast is called similar hue contrast, which is the weakest one. It is often used to highlight the hue of a certain hue and pay attention to the subtle changes of hue.

⑥ Heating and cooling system and contrast: We feel warm for some colors and cold for others. From the color circle, there are blue-green to blue-purple, which gives people a cold impression, and blue is the coldest color;

Warm impressions are red, purple and yellow, of which red and orange are the warmest colors. Visually, the contrast between cold and warm produces a wonderful, vivid and lively color feeling. Cool colors and warm colors can produce spatial effects. Warm colors have a sense of progress and expansion, while cool colors have a sense of retreat and contraction. In artistic expression, both cool colors and warm colors have rich spiritual connotations.

3, purity comparison

Comparing a bright red with a gray red, we can feel the difference in freshness and turbidity. This comparison of color characteristics is called purity comparison. Purity contrast can be reflected in the contrast of different purities in the same tone, and can also be reflected in the contrast of different tones. Compared with pure green, pure red is more vivid. Compared with yellow-green, pure yellow is more vivid. There are two ways to reduce the purity of saturated hue: ① mixing achromatic black and white ash; ② Mix the complementary colors of this color. In the process of changing the purity of a color, whether white, gray or black is added, the hue and cold and warm tendency of the color will change to varying degrees. Generally speaking, some cool colors will get warmer and some warm colors will get colder. A complete purity level can be obtained by increasing the hue with high saturation to a certain proportion so that gray is equal to its brightness until it becomes neutral gray completely. Using this color scale, we can obtain various contrast effects of strong purity and weak purity. The saturated color or nearly saturated color located at both ends of the purity color scale is compared with neutral gray or nearly neutral gray, resulting in strong purity contrast; The contrast with an interval of about 3-5 levels on the color scale belongs to the intermediate contrast of purity; The interval only belongs to 1-2, and the purity is weak. In reality, natural colors and applied colors are mostly unsaturated colors with different gray levels, and subtle changes in hue of each tone will make a color have a new look and mood.

4. Brightness contrast

Each color has its own lightness characteristics. Compared with purple, saturated yellow has a different hue, and there is also a difference between light and shade, which is the brightness contrast of color. Brightness contrast, like the contrast of the other two elements, can be roughly divided into three contrast relationships. The lightness scale with Munsell color is used as a reference standard for grading. The table has 1 1 grades from black to white, in which the color brightness difference is within 3 series, the middle brightness contrast is within 3-5 series, and the strong brightness contrast is above 5 degrees. The cognition of color mainly depends on the relationship between shape and surrounding colors, especially the brightness contrast between them. The stronger the contrast of lightness, the higher the recognition of color and the clearer the graphics. The understanding of color provides us with a basic law: in color composition, the prominent form mainly depends on brightness contrast. Therefore, in order to have a strong influence on the form of a color, it must have a strong brightness difference with the surrounding colors. Conversely, to weaken the influence of a form, it is necessary to narrow the brightness difference between it and the background. These examples all illustrate the influence of lightness contrast on visual form. In order to master the consciousness of color, it is necessary to have the ability to distinguish the brightness of color. It is much more difficult to identify lightness by color than to identify the black, white and gray levels of lightness by achromatic color. Through the analysis of color consciousness, we find that human vision is extremely sensitive to the contrast between light and dark. When there is intensity contrast in the picture, the sharp contrast between light and dark will distract the visual attention from other color effects, which is equivalent to weakening the power of other colors. It is for this reason that all color effects are related to controlling the brightness of colors. Brightness also has an effect on color contrast. When we need to emphasize color contrast, we should try to suppress brightness contrast, and when we want to weaken color contrast, we should increase brightness contrast. In the spatial mixing of colors, when the color points keep a certain area, the weak contrast will blur the shape of the color points, which is easy to cause visual mixing of colors. The hue contrast is strong, but the lightness is close, and the overall effect will be integrated. On the contrary, the shape part will stand out. If we analyze the spatial effect of color from lightness and cold and warm attributes, the color with high lightness and cold and warm will approach forward, while the color with low lightness and cold and warm will retreat. The contrast between lightness and cold and warm will produce the spatial effect of color.

5, color texture

Texture mainly refers to the structural characteristics of the surface of an object. Because the surface texture of materials is different, the ability to absorb and reflect light is also different, so it can affect the color of the surface. The smooth surface has strong reflective ability, unstable color and improved brightness; Rough surface has weak reflective ability and stable color; After being rough to a certain extent, the brightness and purity are lower than the reality. So the same color used in different pigments will produce different color effects. The feeling of texture can be realized by touching and looking. As one of the visual elements, texture refers to the visual texture that can cause people to have different psychological feelings.