On the use of colors in dashboards.
When you design a dashboard you have a number of tools at your disposal. Applying colors is one of them. However overusing colors can have a detrimental
effect. Instead of highlighting the important bits in your dashboard it can have the appearance of a Christmas tree!
For good measure: if I told you I added a red alert in this tree that indicated that you needed to take immediate action. Would you spot it?
(don’t worry, i didn’t )
To make color effective you need to use less of it. For starters, if you start a new design. Begin with grey. Only gradually add colors where it does a good job to convey useful information.
Color can bring your attention to what is important. It also is able to tie things together that belong together. For example Mike Bostock uses color in this example to highlight players that have done exceptionally well. Note how easy it is to notice that they belong together. A part of the reason is that the other colors used are both greyscales
Source: Mike Bostock, http://bost.ocks.org/mike/
Let us look at colors in a more analytical way: There are a couple of different types of color schemes :
Sequential schemes are suitable for data that is ordered from low to high. An example is population density in a chloropleth map or performance in a tree map for stocks
Diverging schemes put most emphasis on the extreme low and the extreme high end of the range. A typical example where you want to use a scheme like this is if you want to decode a versus budget graph. Very high over budget or very low under budget; both deserve emphasis.
Qualitative schemes come in when there shouldn’t be an implied difference between the colors. All categories are to be treated equally. The main goal of these schemes is that as a user you can easily distinguish between the values but together they still look esthetically pleasing.
The example I added to the Diverging Scheme point also lends itself to combine this qualitative scheme with a sequential scheme. For example if you want to assign a color to each region, but the intensity shows for example the number of customers in a part of the region.
Finally on meaning of color. Choosing a color palette can influence the dashboard very much. Color can be split into Earthtones vs unnatural and Cool vs Warm. Making a conscious choice does help your dashboard design.
Source: Juice Analytics
Be aware of the way you want users to perceive your dashboard and pick your colors accordingly. It might just help you to get the users to accept your dashboard.
Finally two links :
If you look for colorschemes Color Trends + Palettes :: COLOURlovers is a good place to start. This is a user community where people submit color schemes for all kinds of designs. Even when you’re not using one of them, just looking around might give you some inspiration
For colors to be used in maps look no further than ColorBrewer: Color Advice for Maps . With a few clicks you’re able to get a range of colors and you will see a preview in the map.