If you are creating maps then for goodness sake
Use sensible colours!
I was helping some undergraduates with some work the other day, and they decided to use the following colour scheme for representing river depth:
- Deep water: Red
- Medium-depth water: Bright green
- Shallow water: Pink
- Deep water: Dark blue
- Medium-depth water: Medium-blue
- Shallow water: Light blue
Isn’t it hard work to come up with nice colour schemes for all of your maps? Nope not at all – ColorBrewer has done it already! If you haven’t used this website already I urge you to do so, it provides a number of carefully-chosen colour-schemes designed for various different purposes. For representing river depth you’d probably want to use one of the blue Sequential schemes, but there are also Diverging schemes for data that goes off in two directions, as well as schemes for representing Qualitative data (those that have no explicit ordering). What’s more you can tell it to only show schemes that are color-blind-friendly, photocopier-safe etc, and it’ll produce a preview for you with various map styles (labels, cities, coastlines etc). All in all it’s very impressive, and very useful.
Plugins and extensions are available for a number of pieces of software to allow ColorBrewer colours to be easily used. These include an ArcGIS plugin (see the bottom answer for how to install with ArcGIS 10), R package, Python module and IDL routines.