I've got normal color vision, and it's bad for me too. If there's more than about a half dozen lines on a graph, chances are two of them are going to be so clos

I've got normal color vision, and it's bad for me too. If there's more than about a half dozen lines on a graph, chances are two of them are going to be so close together that it's a pain to figure out which is which. Visually distinguishing information in graphs can be a very tricky problem, but at the same time, people could easily do a much better job at it if they tried.