Flot Compare Series Plugin
This is a custom Flot Charts plugin which takes a base series and compares it to one or more other series, then modifies the series colors based on the comparison of the values to that base. This would be best used with something like bar charts or my Topbar plugin.
If you have several series, you do not have to compare them all - you can simply enable on a per-series basis. You specify the base series to compare to and the color value of each point based on whether it is greater than or less than the base series.
The following example shows off comparing 2 series and changing color values:
More explanation can be found in the code and on the README of the Repository.