I messed up for a minute there, sorry about that :)

Google maps used to use green or red lines in custom created maps. In satellite view that color had a very bad contrast with the surroundings, especially area's with lots of (green) nature in it. They now use a bright blue, never had any problems with it.

The new bike navigation feature is a bit more difficult. The legend is hidden in it's initial state, making it difficult and confusing to determine what colors are used for the different lines. After checking it appears that they are using a solid black, solid green/red and a dashed green/red line. Works pretty well, but in absence of the legend there is no way of knowing of you're missing something. Minor problem I'd say, but still :)

If you'd run things by me or get in contact with other colorblind people, shoot me a message via twitter (@wearecolorblind) or via the contact page on the website!

Thanks, I made the site and write the articles. If you (or anyone else) has any recommendations for articles or examples of what doesn't work for you, that would immensely help :)

The good/bad ribbons need some color or tone coding. I did not see them at all at first. And they are not very distinguishable.

This. Thank you for making this point :)

Agreed. There are a million area's to focus on, I've focused on getting the site online first as to be able to get the site to grow using feedback like this. So thanks!

The solution itself is indeed difficult, the key is providing information by something other thank color alone. But as you mentioned, you're bound to a single basic shape that can't really differ from the rest.

A clearer color palette might work, but there is no guarantee that it might work for every possible type of colorblindness in every possible situation.

You could use black and white patterns, so as long as a person can distinguish contrast, they should be able to differentiate between the pieces.