When preparing visualisations of data (for business or otherwise), think about what it is you are trying to convey and how easy it is (or not) to determine that information at a glance.

Compare this image depicting the progress of the massive Rimfire in California (source Wired):

Rimfire Progress Palette 1

and this (source Wired):

Rimfire Progress Palette 2

One uses a rather random colour scale for each of the days’  fire progress, where as the second one makes a colour progression reflecting the fire’s progression.

Read more about how this was prepared here:

http://www.wired.com/wiredscience/2013/09/rim-fire-map-color-scale/