When deciding to use color in web design, the first question which comes to mind is: Does Color Really Matter?
Here is an answer: "Research reveals all human beings make a subconscious judgment about an . .. item within 90 seconds of initial viewing and that between 62% and 90% of that assessment is based on color alone."
The above statement from the Institute for Color Research, though a bit overstimated, demonstrates the dominant role that color plays in influencing potential users. Althought in a lot of design cases color is used as a compliment,we know that for better or for worse, color has an overwhelming impact on website viewers.
With the above introduction, we proceed to the main focus of this page, namely the color combination which used for an application. Here, we will introduce ColorBrewer, a web tool for selecting color schemes for thematic maps, most usually for choropleth maps.
ColorBrewer is implemented in Flash. It includes 35 basic schemes with different numbers of classes for over 250 possible versions. Each scheme has CMYK, RGB, Hex, Lab, and AV3 (HSV) specs for the colors. The software is designed simply to list color specs for a scheme you find useful so you are able to create these colors in the mapping software you are using. It is designed specifically for you to look up color sets to use in other mapping environments user is working in. Although this application is specifically designed for mapping, but we believe the recommended color applets can be used in and application.
ColorBrewer contains nice features which let user choose colors most suitable for his own application. Fisrt user must choose the number of map classes he would like to examine. Choosing the number of data classes is an important part of map design. Increasing the number of data classeswill result in a more"information rich" map by decreasing the amount of data generalization. However, too many data classes may overwhelm the map reader with information and distract him from seeing general trendsin the distribution. In addistion, a large number of classes may compromise map legibility: more classes require more colors that become increasingly difficult to tell apart.
Many cartographers advise the user to use five to seven classes.
The next step is to choose the type of schema user wants to examine.
There are three main types of schemas:
- Sequential Schemas: These schemas are suited to ordereddata that progress from low to high. Lightness steps dominates the look of these schemas,with light colors for low data values to dark colors for high values.
- Diverging schemas: They put equal emphasis on mid-range critical values and extremes at both ends of the data range. The critical class or break in the middle of the legend is emphasized with light colors and low and high extremes are emphasized with dark colors that have contrasting hues.
- Qualitative Schemas: They do not imply magnitude differences between legend classes, and hues are used to create the primary visual differences between classes. They are best suited to representing nominal or categirical data.
One intersting feature of the system is a box in the buttom left of the screen. When user chooses any color pallet, the corresponding big legent appears in the lower left. By clicking any of the color spec types above the big legend, the relative color specs will appera to the right of the legend box. Moreover, The icons to the left of the legend in the lower left of the screen suggest contexts in which the particular scheme should work.More specifically:
- If the given color schema will confuse people with red-green color blindness;
- If the given color schema will withstand black and white photography;
- If the given color schema is suitable for the typical LCD room projector;
- If the given color schema is suitable for viewing on a laptop LCD display;
- If the given color schema is suitable for the average CRT screen;
- If the given color schema is suitable for color printing;