Can we avoid calling these 'chart' colours?  Quite possible we'd use them for other stuff, isn't it?

For chart use cases, it doesn't matter what order the colours come in, we just need colours to be distinct, so I suggest:

* Rename this section to 'highlight colours' or something equally generic
* Add a new section to the mapping file to define variables called `ftColor-ChartSeries1`, `ftColor-ChartSeries2` etc, which use the highlight colours.