The [ColorBrewer](http://www.personal.psu.edu/cab38/ColorBrewer/ColorBrewer_intro.html) color tables were designed to provide better color tables than the standard rainbow-type color tables (the rainbow color table is not a very good general color table because, as Tufte points out, "the mind's eye does not readily give an order to ROYGBIV"). There is a nice Flash interface on the web to explore them. But what if you want to use them in IDL?
[Here](http://michaelgalloy.com/wp-content/uploads/2007/10/brewer.zip) are the color tables in a `.tbl` file, usable with the `FILE` keyword in `LOADCT` or `XLOADCT`. For example:
IDL> loadct, 2, file='brewer.tbl'
% LOADCT: Loading table BrBG (Diverging)
There are three types of color tables in the file: sequential, diverging, and qualitative. The qualitative tables are for labeling items and have around ten colors instead of the full complement of 256 colors.
Colors from [`www.colorbrewer.org`](http://www.colorbrewer.org) by Cynthia A. Brewer, Geography, Pennsylvania State University. If you use the color tables in your work, she would like a citation (see 5. on [this](http://www.personal.psu.edu/cab38/ColorBrewer/ColorBrewer_updates.html) page).
UPDATE: I [updated](http://michaelgalloy.com/2008/02/21/updated-brewer-color-tables.html) the color tables to fix problems with the qualitative color tables and added new routines to access the color tables.