Additional Features of Flot
When using the OPC.Flot.buildTrendData() method, all attributes on the Tag Definition are passed through to Flot, and applied to the Flot series object.
In this way, you can set up your series definition within the trend_bindings and they will seamlessly flow through to Flot when the chart is plotted. This is precisely how the label and color attributes are used.
Then, from within any Flot event handlers, those values are available for manual parsing. You can see how this was done in the Interactive Chart example, where the popup label is set to the color defined on the series.
The following links are useful references for the Flot library: