Diverging (Div) color schemes are best for highlighting areas of both high and low rates. They have a neutral color in the middle and darker colors in contrasting hues at the high and low extremes. Diverging color schemes are not good for black and white printing. Available diverging color schemes are:
Red-Yellow-Blue: A commonly used color scheme for disease rate maps. Areas with high rates are red and areas with low rates are blue.
Brown-White-Blue/Green:A useful alternative that avoids using red for areas of high rates (red is seen as a “good” color in many Eastern cultures).
Sequential (Seq) color schemes are good for focusing attention on areas of high rates and for maps that might be printed in black and white. They are based on a single hue with lighter colors for areas with low rates and more intense colors for areas with high rates. Sequential schemes do not support more than 9 intervals. Available sequential color schemes are:
Blue-Green-Yellow: A commonly used color scheme for disease rate maps. With five intervals or fewer, this color scheme has good color separation with most types of viewing devices as well as with color-blind readers.
Red-Orange-White: With five intervals or fewer, this color scheme has good color separation with most types of viewing devices except LCD projectors as well as with color-blind readers. Uses a red-brown for areas with high rates (red is seen as a “good” color in many Eastern cultures).
Additional information about color schemes
The color schemes for this section of the web site have been chosen from the schemes that were developed by Dr. Cynthia Brewer and can be found at: ColorBrewer.org. The individual RGB or HTML color codes are available on the ColorBrewer web site. These color schemes have been tested for use with printers, monitors, and color blind users. One can get more information about ColorBrewer from this journal article: Harrower M., and C. A. Brewer, 2003. ColorBrewer.org: An Online Tool for Selecting Colour Schemes for Maps. The Cartographic Journal, Vol. 40, No. 1, pp. 27–37.