I've been using jqxChart for a bunch of projects and it works okay. It's great if you're working on a fixed set of columns but it can be a bit of a pain if the columns are generated dynamically. But I ran head long into a real problem this week because if you have more than four series on the same graph by default it uses some very similar blue colors.

I figured there must be a better way to do this and after an extremely quick Google search I found this article:

Optimal Colors for Graphs

The article includes this graph which is super helpful if you're using Excel (which the blog post references) but I needed to use it in a CSS document so I needed to convert it from decimal RGB to hex RGB and I figured I could post the results so others could use them.

Bars

Lines and Points