If you have to color a map and are not sure which color palette you should use maybe ColorBrewer comes to your help. This little online tool shows how a color scheme looks in a map and helps you deciding on the right colors which accomplish your needs.
There is a sample map shown and you are guided through three simple steps for coloring the map:
- Step 1: Select the count of needed color classes.
- Step 2: Choose the legend type, either sequential for ordered data from low to high, or diverging which emphasis mid-range critical values or as a last option qualitative with no direct relation between the different color classes.
- Step 3: After Step 2 different color sets are shown. Choose one and the sample map is getting colored with the appropriate color legend.
The interesting part starts after those 3 steps. If a color scheme is chosen the CMYK, RGB, HEX, LAB or ArcView 3.x (GIS format) values can be accessed. That’s great. On top of that additional information is shown if the chosen scheme is suitable for photocopying, LCD projector, laptop screen, CRT screen, color printing or if it will not confuse people suffering from red-green color blindness.
I tried it out and browsed through many color schemes. Most often it showed that the chosen scheme is ok for colorblind people. But when I had a close look at the colors I could definitely tell that I will have some problems with this color scheme. I don’t know where from they got the information if one scheme is confusing and others are not, but they definitely should have taken a bigger test bed or better algorithms.
Maybe they belief that if red and green are not mixed into one color scheme it is not a problem regarding red-green color blindness. This is a misbelief. The tool is ok and can maybe help you out on chosing the right colors. But please don’t trust them regarding the suggestions about color blindness. They are wrong and give a faulty feeling of certainty.