but yet people use red and green to differetiate areas in Google Earth. Here's a screen shot from a well promoted Google Earth project that shall remain nameless to save blushes.
A long time ago I reported talking to a Googler who couldn't even see the borders in this view.
There are a few rules of thumb to help with avoiding color blindness problems in maps:
- If you want to deliniate features using color, choose blends of yellow or blue, very few people have problems with identifying these colors.
- Convert your colors to gray scales, if there is a tonal difference color blind users can still differentiate by tone.
- Think of using different textures to mark areas. Unfortunately this isn't easy to do in Google Earth.