As a rule of thumb, do not blindly accept the default settings in GIS programs. Rule of Thumb Default settings in GIS programs should not be accepted blindly. Boilerplate maps, produced regularly to show specific needs such as weekly precinct or division crime patterns, can be fine tuned so they consistently convey the intended message. Problems are more likely to arise with specialized maps. Note that some icons are awkward shapes and may have a minimum size, below which they become meaningless.
Misused color detracts from an otherwise excellent map.
Excessive use of bright colors may hurt the eye and repel the reader. Illogical color gradations may be confusing. Think about how the map will be used. Color may be irrelevant if the map is to be distributed by fax or printed in a document that will not be reproduced in color. In such cases, color can be counterproductive.