ColorBrewer: Online Tool for Helping Non-Experts Select Good Color Schemes for Thematic Maps
Research conducted by Cindy Brewer and Mark Harrower.

Website: www.ColorBrewer.org

Choosing a good color scheme for a thematic map is a daunting prospect. A successful color scheme must be attractive and logical, support the message of the map, and reflect the nature of the data. Inexperienced mapmakers often choose random colors to depict an orderly data sequence, incorporate large perceptual jumps when none are warranted, and choose a sequential color scheme for categorical data. Mapmakers must also understand the limitations of the display medium - color schemes that look great on a CRT may not work with a LCD monitor or a laser printer. And increasing the number of data classes increases the chance that a color scheme will fail. Unfortunately, commercial mapping software seldom provides color-use guidelines. We have developed an online mapping tool that takes some of the guesswork out of this process. Built in Flash 5, ColorBrewer is a dynamic tool recommends and displays (as both map and legend) professional schemes appropriate to the number of data classes, the nature of the data, and the display medium. Users can adjust map properties such as background color, border color, and map scale and can overlay symbols to test the robustness of a scheme. The maps serve as diagnostic tools - orderly and random color patterns prompt users to check if each color in the sequence is legible across the map. Mini-tutorials are embedded throughout the interface. RGB, CMYK, hexadecimal, and CIE Lab specifications are displayed on-screen and can be exported as printer-friendly and XML files. ColorBrewer is provided free-of-charge at www.ColorBrewer.org