Color blindness is a kind of disease that cannot correctly identify some or all of the colors. Because color blindness is lack of the ability of identifying color, the map content that they see is different from what the ordinary people see. That will cause that the information of map cannot be conveyed to the color-blind people perfectly and accurately. Therefore, the color-blind people need a special way of map color design. The following is the map color selection principles for color-people. At first, select the color combination that is not easy to confuse. According to the identification ability of the different types of color-blind people, the map should adopt the color combination that is easy to distinguish. For example, for red blindness, it is easy to distinguish between blue and green. Increase the color contrast and make a difference in lightness and purity. Color-blind people is not sensitive to color contrast, and it is a good way to increase the color contrast. Choosing effective contrast color can improve the reading resolving ability of color-blind people. To some extent, some bright colors are always more dark than the actual in the eyes of color-blind people. In color selection, the map should try to make adjustments on the lightness and purity and that can make color-blind people better identify the color. Add the annotation and texture to the map. About dot color. Dot color is the color of showing point symbol of the point data. Because the symbols can be used as a fixed-point notation, including the color of statistical chart. For quality difference, using the different hue to show. According to the identification ability of the different types of color-blind people, the map should adopt the color combination that is easy to distinguish. Such as yellow instead of red and green. Avoid using the combination of red and green and use carmine or purple instead. In view of the phenomenon of dynamic change, use the color gradient to show. Dot notation should use the color original and use less compound color, which is easy to identify for color-blind people. The symbol of structure often use the big difference of color combination, and to pay attention to increasing the brightness contrast. Such as green blindness, using blue and yellow to show the symbol of structure can achieve a good visual effect. About line color. Line color is the color of linear symbol including boundaries, linear object symbols and movement line. Boundaries are not entity symbol, but they are divided into primary part and secondary part. Main boundaries should use the color that is relatively sensitive, have a high concentration and brighter color lightness for color-blind people. As for the red color blindness, blue and yellow is very sensitive color to identify easily. Secondary boundaries can use the color that it is not easy to identify, its concentration is smaller and the color lightness is darker. As for red color blindness, blue-green appears to be shallow gray, and it is suitable for this kind of color to represent the secondary boundaries. Linear objects symbols and movement lines of color selection should also be divided into main and secondary part according to the map purpose. Their color selection with boundaries are consistent. About planar color, planar color is to use colors within a certain scope of area. It is divided into regional background, color level background and foil color. As for the regional background, it use different color, hachure and decorative pattern to show the region. It does not mean any the quality and quantity, the purpose of using the color lie in some region which is not divided into main and secondary parts. As for the color level background, it show quantitative relationship according to color gradations of color gradient, and the process of showing number give priority to the change of the brightness, the hue that can be identified is complementary. A map possess a good the ability of identification, not only can make color-blind people improve the quality of reading but also can increase the possibility of repeated reading. Therefore, the study of color selection is very necessary in the process of map color design. It can make map makers pay attention to the need of color-blind people to select color scientifically and make the universal design. The development of tactile map. |
